Effect of TiO2 Compact Layer on DSSC Performance

Dye-sensitized solar cells offer an economically reliable and suitable alternative in moderating the challenges presented by the existing convectional photovoltaic cells. Whereas, for convectional solar cells the semiconductor adopts both the duty of light absorption and charge carrier transport, these two functions are separated in dye-sensitized solar cells. However, the efficiency of dye-sensitized solar cells has remained relatively low. For this reason, this research was aimed at how to increase the dye-sensitized solar cells performance. To achieve this, compact cover of TiO2 was deposited on a conductive glass substrate by using Holmarc’s Spray Pyrolysis system, using Ultrasonic Spray Head and spraying in vertical geometry, while TiO2 nanoparticles and nanotubes were deposited by screen printing technique on top of a transparent conducting FTO glass slide with or without the TiO2 compact layer. Transmission characteristics showed that introducing TiO2 compact layer on the conductive film lowers the transmission while reflectance properties were less than 15 % for all the prepared thin films. SEM micrographs showed that TiO2 nanotubes had a skein-like morphology with abundant number of nanotubes intertwined together to form a large surface area film. Solar cell performance properties revealed that introducing compact layer to dye-sensitized solar cells improved the performance by 145 % (from 1.31 % to 3.21 %) while TiCl4 treatment on compact layered dye-sensitized solar cells increased the efficiency by 28.79 % (from 0.66 % to 0.85 %)

And Wrote My Story Anyway: Black South African Women’s Novels as Feminism

No Abstract

A mobile application (I-Masomo) for enhancing information access for university course selection in Kenya

Conference presented at 2014 eLearning Innovations Conference and Expo-KenyaThe use of Mobile device in our everyday life has become inevitable due to their availability, affordability, portability and network coverage. In learning, mobile devices present a solution to a number of educational problems (West, 2013). Mobile phones, smart phones, tablets and Personal Digital Assistant (PDA) are all examples of mobile devices. This category of mobile devices may serve multiple purposes. Apart from the traditional use of sending and receiving voice communication, the devices may have advanced features such as internet access; take pictures, play music and some are even equipped with Global Positioning Services (GPS) functionality and many more. According to Jacobs (2013), while mobile technologies provides a way of accessing academic content effectively, students can extend learning beyond the classroom environs while collaborating and sharing with peers. Teachers can also guide students in active learning beyond the standard class times. This paper is based on a mobile application developed at iLabAfrica as part of a Masters dissertation. The main objective of this research was to develop a mobile application and a web portal that would assist students, parents and guardians in decision making through access of relevant information in relation to university courses and admission requirements. To enhance access to university information, a mobile application “i-Masomo” was designed, developed and tested. In addition, a web portal was also incorporated to ease information access and decision making from a central point. Consequently, it aims to collate and avail such information on a platform accessible to the students, as well as other interested parties, via mobile phones and web platforms. In Kenya, there has been an increase in demand to access university education. This has been attributed mainly to the increase in number of candidates who obtain the minimum university entry requirement grade of C+ and above in the Kenya Certificate of Secondary Education examination. The need to identify the right course and career of choice is evident despite the few slots offered in public universities. This study addresses the recurring problem of students seeking admission to Kenya’s public universities having to manually peruse through large volumes of University Calendar entries in search of their desired degree programs and the requisite requirements for admission to such programs. In Kenya, there is still no integrated system that can be used to identify the right course based on the performance of a student. This paper describes the step by step design and development techniques and process of the i-Masomo mobile application and the web portal. The findings of this study express that majority of prospective students, parents and teachers access academic related information from the internet. The study also ascertains that the i-Masomo mobile application and the web portal has a significant potential in dissemination of information about university course selection and university enrollment in Kenya.The use of Mobile device in our everyday life has become inevitable due to their availability, affordability, portability and network coverage. In learning, mobile devices present a solution to a number of educational problems (West, 2013). Mobile phones, smart phones, tablets and Personal Digital Assistant (PDA) are all examples of mobile devices. This category of mobile devices may serve multiple purposes. Apart from the traditional use of sending and receiving voice communication, the devices may have advanced features such as internet access; take pictures, play music and some are even equipped with Global Positioning Services (GPS) functionality and many more. According to Jacobs (2013), while mobile technologies provides a way of accessing academic content effectively, students can extend learning beyond the classroom environs while collaborating and sharing with peers. Teachers can also guide students in active learning beyond the standard class times. This paper is based on a mobile application developed at iLabAfrica as part of a Masters dissertation. The main objective of this research was to develop a mobile application and a web portal that would assist students, parents and guardians in decision making through access of relevant information in relation to university courses and admission requirements. To enhance access to university information, a mobile application “i-Masomo” was designed, developed and tested. In addition, a web portal was also incorporated to ease information access and decision making from a central point. Consequently, it aims to collate and avail such information on a platform accessible to the students, as well as other interested parties, via mobile phones and web platforms. In Kenya, there has been an increase in demand to access university education. This has been attributed mainly to the increase in number of candidates who obtain the minimum university entry requirement grade of C+ and above in the Kenya Certificate of Secondary Education examination. The need to identify the right course and career of choice is evident despite the few slots offered in public universities. This study addresses the recurring problem of students seeking admission to Kenya’s public universities having to manually peruse through large volumes of University Calendar entries in search of their desired degree programs and the requisite requirements for admission to such programs. In Kenya, there is still no integrated system that can be used to identify the right course based on the performance of a student. This paper describes the step by step design and development techniques and process of the i-Masomo mobile application and the web portal. The findings of this study express that majority of prospective students, parents and teachers access academic related information from the internet. The study also ascertains that the i-Masomo mobile application and the web portal has a significant potential in dissemination of information about university course selection and university enrollment in Kenya

Optical Properties and Analysis of OJL Model’s Electronic inter-band Transition Parameters of TiO2 Films

Titanium dioxide is a wide band gap semiconductor responsible for the bright white appearance in most substances. This material has many unique properties due to its extra-ordinary chemical stability. TiO2 has a conduction band that closely matches the excited energy level of organic dyes hence it is used in fabrication of photo-anode electrode of dye sensitized solar cell. However, the optical properties and the density of states of TiO2 thin films determine the performance of dye sensitized solar cell fabricated from TiO2 photo-anode electrode. For this reason, the purpose of this study was to investigate the optical properties and the OJL electronic inter-band transition analysis of TiO2 nanoparticle thin films. Under the OJL model, the expressions of density of states were specified for the optical transition from the valence band to the conduction band. The TiO2 nanoparticles were prepared using sol-gel and hydrothermal methods and deposited on a conductive glass substrate by screen printing and spray pyrolysis techniques. SEM analysis revealed that TiO2 nanoparticles were spongy and had unevenly sphere-shaped profile while TiO2 nanotubes had a skein-like morphology with abundant number of nanotubes intertwined together. This study showed that TiO2 thin films have both direct and indirect band-gaps. The OJL Gap energy (E0) values were observed to be between 30273.2356 and 31072.0000 wavenumbers which translated to band-gap energies between 3.744 and 3.843 eV. From these findings showed that TiO2 films prepared could be used in the fabrication of high performing dye-sensitized solar cell

Evaluating Factors Affecting Clinicians’ Knowledge on Contrast Media: Kenyan Experience

Purpose: Our study aimed to establish exposure to and level of knowledge about contrast media among non-radiological clinicians and evaluate the contributory factors to the status. Methods and Materials: A cross-sectional study was conducted between April and December 2015 through interviews using structured questionnaires. We recruited 197 non-radiological clinicians with experience in use of contrast media in their routine practice. They were of different cadres and years of experience, all working in a large referral hospital in Kenya. Levels of basic knowledge on contrast media were evaluated through a scoring system after each clinician responded to the questions provided. We also sought for training on contrast media among these clinicians and where applicable the source of the same recorded. Descriptive and inferential statistical methods were applied across the different clinicians’ subsets. Results: Thirty-seven respondents representing 18.8% of the study sample had received formal training on contrast media. Mean knowledge score for all clinicians in this study was 14.6 translating to 14.1% of a set maximal theoretical score of 103 points. The standard deviation was 5.5. Analysis of variance (ANOVA) test for knowledge mean score among different cadres gave a P value 0.079. Unpaired t-test gave a two- tailed P value 0.2410 for mean score when trained and untrained clinicians were compared. The level of knowledge (mean score) when analysed against years of experience for the clinicians produced statistically significant results with P value 0.001084. Conclusion: Training and knowledge on contrast media can be profoundly low for clinicians. However, there is a possibility of knowledge improving from experience in practice due to multidisciplinary interaction and the implied advantage of encapsulated knowledge

Can guidelines improve referral to elective surgical specialties for adults? A systematic review

Aim To assess effectiveness of guidelines for referral for elective surgical assessment. Method Systematic review with descriptive synthesis. Data sources Medline, EMBASE, CINAHL and Cochrane database up to 2008. Hand searches of journals and websites. Selection of studies Studies evaluated guidelines for referral from primary to secondary care, for elective surgical assessment for adults. Outcome measures Appropriateness of referral (usually measured as guideline compliance) including clinical appropriateness, appropriateness of destination and of pre-referral management (eg, diagnostic investigations), general practitioner knowledge of referral appropriateness, referral rates, health outcomes and costs. Results 24 eligible studies (5 randomised control trials, 6 cohort, 13 case series) included guidelines from UK, Europe, Canada and the USA for referral for musculoskeletal, urological, ENT, gynaecology, general surgical and ophthalmological conditions. Interventions varied from complex (“one-stop shops”) to simple guidelines. Four randomized control trials reported increases in appropriateness of pre-referral care (diagnostic investigations and treatment). No evidence was found for effects on practitioner knowledge. Mixed evidence was reported on rates of referral and costs (rates and costs increased, decreased or stayed the same). Two studies reported on health outcomes finding no change. Conclusions Guidelines for elective surgical referral can improve appropriateness of care by improving prereferral investigation and treatment, but there is no strong evidence in favour of other beneficial effects

Comparison between the outcome of trial of labour and elective repeat caesarean section in Kiambu district hospital: a retrospective cohort study

Objective: To determine the pregnancy outcomes in patients with one previous Caesarean section scar who underwent trial of labour as compared to those who had elective repeat Caesarean section at Kiambu District Hospital.Design: A retrospective cohort study.Setting: Post natal wards of Kiambu District Hospital.Subjects: Medical records of all mothers with one previous Caesarean section scar who had delivered in Kiambu District Hospital were obtained and the information used to fill questionnaires. Maternal morbidity was assessed primarily based on post-natal hospital stay. Other maternal morbidity measures assessed included occurrence of uterine rupture, maternal death, need for hysterectomy, maternal blood loss, presence of visceral injury (bladder or gut) and post delivery infectious morbidity. In addition, the failure rate of trial of labour was determined. Foetal outcome was assessed based on APGAR score at five minutes, need for admission to the new born unit and the occurrence of early neonatal death.Results: A total of 142 participants were recruited of which 71 had undergone TOL and 71 had undergone ERCS. Clinical pelvimetry was the most common criteria used for selection of patients for TOL since 100% of all patients in the TOL group were assessed this way as compared to 80.3% in the ERCS group. The success rate of TOL was 50.7% in this study. Successful TOL was associated with less hospital stay since 91.6% stayed for two days or less as compared to ERCS where 84.5% stayed for 3-4days (P<0.001). Similarly, blood loss was less for those who had successful TOL where 97.2% lost less than 500mls as compared to ERCS where 85.9% lost 500mls or more. Maternal outcomes were worse in the 49.7% who failed TOL since only 57.1% of them had a post-natal hospital stay of three to four days as compared to 84.5% in the ERCS group( p=0.029) and 42.9% of the failed TOL group stayed in the hospital for five days or more as compared to only 15.5% in the ERCS group(p=0.002). Foetal outcome was worse in the TOL group since 11.3% had an APGAR score of less than eight at five minutes as compared to only 1.4% in the ERCS group(p=0.016). Similarly, 14.1% of newborns in the TOL group were admitted to the new born unit as compared to only 5.6% in the ERCS group(p=0.091). There were no early neonatal deaths reported in both groups.Conclusion: Overall success rate for TOL was low necessitating emergency Caesarean section of which the maternal outcomes were worse than in the ERCS group. The foetal outcomes were better in the ERCS group as compared to the TOL group.

Treatment of African children with severe malaria - towards evidence-informed clinical practice using GRADE

<p>Abstract</p> <p>Background</p> <p>Severe malaria is a major contributor of deaths in African children up to five years of age. One valuable tool to support health workers in the management of diseases is clinical practice guidelines (CPGs) developed using robust methods. A critical assessment of the World Health Organization (WHO) and Kenyan paediatric malaria treatment guidelines with quinine was undertaken, with a focus on the quality of the evidence and transparency of the shift from evidence to recommendations.</p> <p>Methods</p> <p>Systematic reviews of the literature were conducted using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool to appraise included studies. The findings were used to evaluate the WHO and Kenyan recommendations for the management of severe childhood malaria.</p> <p>Results</p> <p>The WHO 2010 malaria guidance on severe malaria in children, which informed the Kenyan guidelines, only evaluated the evidence on one topic on paediatric care using the GRADE tool. Using the GRADE tool, this work explicitly demonstrated that despite the established use of quinine in the management of paediatric cases of severe malaria for decades, low or very low quality evidence of important outcomes, but not critical outcomes such as mortality, have informed national and international guidance on the paediatric quinine dosing, route of administration and adverse effects.</p> <p>Conclusions</p> <p>Despite the foreseeable shift to artesunate as the primary drug for treatment of severe childhood malaria, the findings reported here reflect that the particulars of quinine therapeutics for the management of severe malaria in African children have historically been a neglected research priority. This work supports the application of the GRADE tool to make transparent recommendations and to inform advocacy efforts for a greater research focus in priority areas in paediatric care in Africa and other low-income settings.</p

Potential tree species extinction, colonization and recruitment in Afromontane forest relicts

Tree species regeneration determines future forest structure and composition, but is often severely hampered in small forest relicts. To study succession, long-term field observations or simulation models are used but data, knowledge or resources to run such models are often scarce in tropical areas. We propose and implement a species accounting equation, which includes the co-occurring events extinction, colonization and recruitment and which can be solved by using data from a single inventory. We solved this species accounting equation for the 12 remaining Afromontane cloud forest relicts in Taita Hills, Kenya by comparing the tree species present among the seedling, sapling and mature tree layer in 82 plots. A simultaneous ordination of the seedling, sapling and mature tree layer data revealed that potential species extinctions, colonizations and recruitments may induce future species shifts. On landscape level, the potential extinction debt amounted to 9% (7 species) of the regional species pool. On forest relict level, the smallest relicts harbored an important proportion of the tree species diversity in the regeneration layer. The average potential recruitment credit, defined as species only present as seedling or sapling, was 3 and 6 species for large and small forest relicts, while the average potential extinction debt was 12 and 4 species, respectively. In total, both large and small relicts are expected to lose approximately 20% of their current local tree species pool. The species accounting equations provide a time and resource effective tool and give an improved understanding of the conservation status and possible future succession dynamics of forest relicts, which can be particularly useful in a context of participatory monitoring

Restorative justice in international criminal law: the rights of victims in the international criminal court

Since the International Military Tribunal (IMT) at Nuremberg, the first international tribunal to try individuals for international crimes, the role of victims of international crimes in international criminal proceedings has been limited to that of witnesses. The ad hoc international tribunals – the International Criminal Tribunal for the former Yugoslavia (ICTY), the International Criminal Tribunal for Rwanda (ICTR) and the Special Court for Sierra Leone (SCSL) did not change this position. As such, the International Criminal Court (ICC) is the first international criminal tribunal to provide for the rights of victims to participate in their own right in criminal proceedings. Similarly, it is the first such tribunal to provide for the right to reparations. This thesis focuses on the right of victims to participation and to reparations under the Rome Statute of the International Criminal Court. It argues that the ICC offers an opportunity for the entrenchment of the concerns of victims in the international criminal process. However, it suggests that this depends on what framework of justice the Court adopts. The thesis further argues that previous international criminal tribunals – the IMT at Nuremberg and the ad hoc International Criminal Tribunals (ICTY, ICTR and SCSL) – operated on retributive and utilitarian theories of criminal justice that are exclusionary of and inimical to specific concerns of victims of international crimes. The largely retributive and utilitarian objects driving these systems limited victims to a peripheral status in the process and failed to address fully the harm occasioned to victims. This thesis suggests that the ICC should adopt a restorative justice paradigm in order to give full effect to the rights of victims while protecting the rights of defendants and meeting the law enforcement functions of the Court. The thesis reviewed the relevant texts – the Rome Statute, its Rules of Evidence and Procedure and other instruments – and demonstrated the fact that the ICC framework provides a basis for such a restorative justice paradigm. In order to suggest a trajectory for the operationalisation of the ICC victims’ rights regime underpinned by principles of restorative justice, the thesis attempts a systematic review of the rights of victims in criminal law processes in select domestic criminal justice systems, international human rights tribunals and other international courts. At the same time, the thesis reviews the implementation of reparations in various contexts and made suggestions as to how the ii ICC and the Victim Trust Fund (VTF) should proceed in this regard within the relevant legal and institutional framework. In relation to the right to participate, the thesis concludes that Article 68(3) of the Rome Statute – the general provision on the subject – strikes the right balance between the right of victims to participate, defence rights to an expeditious trial and the law enforcement function of the Prosecutor. However, the scope of victim participation at various stages of the proceedings will depend on, among others, the paradigm of justice adopted by the Court and, in view of the Prosecutor’s seemingly knee-jerk opposition to victim participation, the attitude adopted by the Court itself to this new right of victims to participate. The thesis reviewed relevant texts and concluded that the Rome Statute’s victims’ rights regime presupposes a restorative model of justice – understood as values and principles rather than ‘practices’ and ‘methods’ as applied in some national criminal justice systems. Restorative justice contemplates a central role for victims of crime in relevant proceedings. Henceforth, the rights of defendants must not only be weighed against the concerns of the Prosecutor but also the right of victims to participate. The thesis concluded further that the tests established for victims’ participation – appropriateness, the requirement for their personal interests to be affected and the rights of defendants – present serious challenges in view of the fact that ICC crimes for the most part will involve mass atrocity. The number of victims who may eventually participate in particular proceedings is thus very small. The thesis notes that while the provision for legal representation of victims alleviates some of the difficulties associated with participation by a varied mix of victims in complex proceedings, it may be considered as diminishing the impact of direct participation. While the scope and modes of victim participation will vary at various phases of proceedings, current jurisprudence at the ICC shows that the Court seems to favour a broad presumption of victim participation. Since full realisation by victims of the right to participate will depend on the role that the Court will play, it is crucial that the right paradigm of justice is adopted. With respect to the right to reparations, the thesis notes that this is perhaps the greatest innovation in the Rome Statute. The study found that the Rome Statute establishes two ‘focal points’ for purposes of reparations – the Court and the Victim Trust Fund (VTF) – in close relationship with each other. Drawing from the iii experience of national criminal justice systems, the thesis acknowledged the practical difficulties involved in vesting a criminal court with a reparation function will pose particular challenges for the Court. These include the need to protect the right of a defendant to a speedy trial, the presumption of innocence and to conduct efficient proceedings. Having reviewed the texts and relevant jurisprudence, the study concluded that various mechanisms, including various permissive rules and the creation of the VTF make it possible to address some of the difficulties associated with the right to reparations in the ICC. The thesis further noted that while a reading of the relevant provisions establishes the possibility of the Court and VTF instituting independent reparations schemes, it is imperative that the two collaborate in order to give full effect to that function. In any case, while Regulation 56 of the Court’s Regulations provides for the possibility of considering reparations issues during the main trial, the fact that a reparation order against an accused is dependent on finding of guilt of the accused, it necessarily means that a definitive finding on reparation has to come after that. Further, the thesis concluded that in context of mass atrocities and the possibility that numerous victims may prove the requisite links to a case to obtain reparations, holding joint proceedings would complicate and burden the trial. However, the thesis endorsed the initial view of the Court that evidence concerning reparations could, at least in part – where appropriate, and in the interest of efficiency and victims – be considered during the trial. The thesis further concluded that the VTF, which presents greater flexibility than the Court in terms of standards of proof, the requirement for criminal liability and various other mechanisms should be allowed a more prominent role in the processing of reparations. A survey of various mass reparation schemes – Holocaust reparations, South African TRC, the Rwandan Gacaca model and the United Nations Compensation Commission (UNCC), as well as the Alien Tort Claims Act (ATCA), a particular mass tort litigation mechanism – offer some useful lessons on a range of challenging reparation related questions. The study concluded that while the Rome Statute offers an important opportunity for victims in terms of reparations, various challenges including shortage of funds and the large number of victims requires that situation countries – those states under investigation by the ICC and from which victims are drawn – cannot abandon iv their primary responsibility of providing appropriate remedies for victims. The ICC is not, and cannot be a panacea for the concerns of victims of international crimes