1,451 research outputs found

    Waste Biomass Densification for Thermochemical Conversion

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    Waste biomass densification into briquettes and pellets improves the characteristics of loose biomass residue for efficient transport, storage and thermochemical conversion into advanced fuels (e.g., syngas, for electricity, liquid fuels and chemicals). Briquettes of good and consistent quality are required but often difficult to achieve as more work is still required to understand how the chemical and physical properties of different biomass types, along with process variables, affect their quality. Also, the additional energy and cost associated with biomass briquetting has raised the issue of the sustainability of briquetting loose biomass before its conversion. This research focuses on the use of novel approaches to improve the quality of fuel briquettes for thermal applications, and further evaluates the sustainability of fuel briquetting, using life cycle assessment (LCA). Experiments were conducted to investigate the potential benefits of blending waste rice husks, corn cobs and bagasse, and with novel binders including enhanced treated biosolids, and microalgae (Chlorella sorokiniana), on fuel briquette properties, using factorial design methods. The new binders were also compared with existing starch binder. The range of briquettes produced in this study had unit densities of up to 3.3 times the loose biomass bulk density, and were stronger than briquettes from the individual biomass materials. Considering average values from two biomass sources, an unconfined compressive strength of 176 kPa was achieved at a compaction pressure of 31 MPa for a 3:7 blend of rice husks to corn cobs with 10% binder (starch + water). These briquettes were durable, with only 4% mass loss during abrasion, and 10% mass loss during shattering, tests. They absorbed 36% less water than loose corn cobs. An unconfined compressive strength of 175 kPa was also achieved for a 2:4:1 blend of rice husks, corn cobs and bagasse with 17% binder (microalgae), also at a compaction pressure of 31 MPa. The statistical analysis of the above results showed that the source of the biomass had a significant effect on densification, which emphasises the need to understand factors underlying biomass variability. Of all the briquettes produced with the three binders, those containing the microalgae binder were found to be most durable, with a higher energy density, slower mass loss during briquette combustion, and a higher afterglow time. Since microalgae may be grown using CO2 from biomass combustion, discovery of their advantages as a binder in briquetting is particularly welcome. To evaluate the sustainability of fuel briquetting, a detailed review of the existing LCA studies on fuel briquetting was carried out. These were found to provide insufficient and inconsistent information, due to different choices in system boundary, data sources, functional unit, allocation procedure, briquetting technology and biomass/briquette properties. An LCA model of biomass briquetting was therefore developed to enable transparent comparison of life cycle environmental impacts of briquetting with individual or blends of biomass feeds with a variety of technological options. The main model components include materials and process inventory databases derived from standard sources, main process calculations, user inputs and results sections. The model is open-access in a user accessible format (Microsoft Excel). A representative case study with mixed rice husks and corn cobs showed that the briquetting unit itself made the largest contribution, 42%, to the total life cycle operational energy of the briquetting system. For all the blends of rice husks and corn cobs explored in this study, the total life cycle energy of briquetting was in the range 0.2 to 0.3 MJ per MJ of fuel briquette energy content. Variation of the LCA input parameters in a sensitivity test for the same blend ratios, gave a range of total life cycle energy of briquetting from 0.2 to 1.7 MJ per MJ of fuel briquette energy content. This indicates that energy use in briquetting is not necessarily recovered, highlighting the need for continuous process optimisation and high quality LCA data. An increase in rice husks content of the blend increased the environmental impact of briquetting including the global warming potential (kg CO2-eq), acidification potential (kg SO2-eq), human toxicity (kg 1,4-DB-eq), ozone layer depletion (kg CFC-11-eq), and terrestrial ecotoxicity (kg 1,4-DB-eq) per MJ briquette energy content, as it was associated with a lower briquette density, which increased the energy required for handling

    Profile of genetic disorders prevalent in northeast region of Cairo, Egypt

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    As clinical geneticists, we recently reviewed our 43 years experience in an attempt to represent the frequency of genetic disorders in the Division of Genetics at Pediatric Hospital, Faculty of Medicine, Ain-Shams University, Cairo, Egypt, during the period from 1966 to 2009. All patients (from birth up to 18 years) suspected of having a genetic disorder were referred to the Genetics Clinic in the same hospital. 28,689 Patients were proved to have genetic disorders after full investigations among 660,280 children attending the Pediatrics Hospital which constituted 4.35% or 43.5/1000. Neurologic disorders were the most common (31.38%) followed by hematologic disorders (18.48%), chromosomal abnormalities (11.51%), fetal, neonatal and infant deaths (6.56%), special senses (5.82%), inborn errors of metabolism (4.24%), endocrine disorders (3.87%), skeletal disorders (3.17%), genito-gonadal anomalies (3.10%), neuromuscular disorders (2.86%), syndromes (2.08%), genodermatoses (1.92%), cardiac disorders (1.47%), gastrointestinal tract anomalies (1.37%), renal anomalies (0.26%), connective tissue disorders (0.26%), respiratory defects (0.22%), vascular anomalies (0.21%), and immunologic disorders were the least common (0.19%).Keywords: Genetic disorders; Congenital malformations; Inbreeding profile; Northeast region; Cairo; Egyp

    Vaccines and immunization: The past, present and future in Nigeria

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    Vaccines are arguably the most important public health tools available today. Since the successful eradication of smallpox with the use of the vaccine, many vaccines have become available to man. Of great importance to public and child health are the vaccines against the so-called six killer diseases of childhood-measles, pertussis, diphtheria, tetanus, tuberculosis and poliomyelitis. In the last 2 decades, effective vaccines against the major causes of pneumonia, another childhood killer, have become available. Data from many parts of the world including African countries have shown the benefits of the pneumococcal and Haemophilus influenzae type b vaccines. The scientific world is still searching for appropriate candidate vaccines for malaria and HIV infection. Despite the availability and effectiveness of many vaccines, the benefits to a country is highly dependent on a viable and sustainable health system which include adequate financing, dynamic and motivated workforce, strong partnerships and effective community participation. If well deployed, available vaccines as elucidated in this discourse can accelerate the achievements of the Millennium Development Goals in Nigeria and many other developing countries.Key words: Vaccines, Immunizations, Nigeria

    Analisis Penetapan Standar Biaya Pendidikan Pada SMA Negeri 2 Kuala Kabupaten Nagan Raya

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    : Determination of standard cost of education is a criterion for good measure the overall expenditure in the form of cash and non-cash as an expression of the sense of responsibility of all parties (the public, parents, and government) to the development of education in order to achieve educational goals efficiently and effectively. The purpose of this study was to determine the ability of the principal to establish the cost of education, including: (1) Preparation of the cost of education; (2) The use of the cost of education; and (3) Auditing the cost of education. This study used a qualitative approach with descriptive methods, techniques of data collection is done through interviews, observation, and documentation. Subjects were principal, treasurer and inspectorate Nagan Raya. The research found: (1) Preparation of educational costs through Plan Budget (RKA) and Draft Budget Shopping Opinions School (budgets) are discussed in a budget meeting in the DPRK; (2) The use of the cost of the education budget comes from the state budget, and the budget and other sources of educational expenses of parents, private, business, and alumni of the largest education budget priorities is to pay the salaries of teachers / employees, which is between 75-80% of the total budget, and the rest for non-teachers' salaries; and (3) the cost of education is an activity Auditing look carefully, investigate, study, examine and investigate the cost of education, including procedures for investigating its books, one truth in a case, the events that have been recorded, placed on their posting, as well as the receipt of cash flows and goods owned by a school organized by the government and society. It is expected that the inspectorate in order to direct and supervise the principal standard-setting the cost of education on the preparation, use, and effective auditing and efficiency so that the cost of education in school on target

    Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

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    Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease

    Determinants of patient preferences for total knee replacement: African-Americans and whites

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    Introduction: Patient preferences contribute to marked racial disparities in the utilization of total knee replacement (TKR). The objectives of this study were to identify the determinants of knee osteoarthritis (OA) patients' preferences regarding TKR by race and to identify the variables that may mediate racial differences in willingness to undergo TKR. Methods: Five hundred fourteen White (WH) and 285 African-American (AA) patients with chronic knee pain and radiographic evidence of OA participated in the study. Participants were recruited from the community, an academic medical center, and a Veterans Affairs hospital. Structured interviews were conducted to collect socio-demographics, disease severity, socio-cultural determinants, and treatment preferences. Logistic regression was performed, stratified by race, to identify determinants of preferences. Clinical and socio-cultural factors were entered simultaneously into the models. Stepwise selection identified factors for inclusion in the final models (p < 0.20). Results: Compared to WHs, AAs were less willing to undergo TKR (80% vs. 62%, respectively). Better expectations regarding TKR surgery outcomes determined willingness to undergo surgery in both AAs (odds ratio (OR) 2.08, 95% confidence interval (CI) 0.91-4.79 for 4th vs. 1st quartile) and WHs (OR 5.11, 95% CI 2.31-11.30 for 4th vs. 1st quartile). Among AAs, better understanding of the procedure (OR 1.80, 95% CI 0.97-3.35), perceiving a short hospital course (OR 0.81, 95% CI 0.58-1.13), and believing in less post-surgical pain (OR 0.73, 95% CI 0.39-1.35) and walking difficulties (OR 0.66, 95% CI 0.37-1.16) also determined willingness. Among WHs, having surgical discussion with a physician (OR 1.96, 95% CI 1.05-3.68), not ever receiving surgical referral (OR 0.56, 95% CI 0.32-0.99), and higher trust in the healthcare system (OR 1.58, 95% CI 0.75-3.31 for 4th vs. 1st quartile) additionally determined willingness. Among the variables considered, only knowledge-related matters pertaining to TKR attenuated the racial difference in knee OA patients' treatment preference. Conclusions: Expectations of surgical outcomes influence preference for TKR in all patients, but clinical and socio-cultural factors exist that shape marked racial differences in preferences for TKR. Interventions to reduce or eliminate racial disparities in the utilization of TKR should consider and target these factors

    Sero-Prevalence of Cytomegalo Virus Antibodies in Pregnant Women Attending Two Selected Hospitals in Sokoto State, North-Western Nigeria

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    Infection with cytomegalo virus (CMV), especially in pregnancy may cause pregnancy complications such as congenital infection, non-hereditary deafness, intrauterine growth restriction and other high defects. This study was to evaluate the prevalence of CMV in pregnant women attending Antenatal Clinics at Maryam Abacha Women and Children Hospital (MAWCH) and Sokoto Specialist Hospital (SSH). The study enrolled 90 pregnant women (age range: 16-45 years old) and data on demographic and life styles obtained using structured questionnaire. Serum samples were assayed using CMV Ig-G EIA kit. Out of the 90 pregnant women examined, 88(97.8%) had IgG protective antibodies to CMV while 2(2.2%) did not have protective antibodies. The prevalence rate of 2.20% was obtained in pregnant women that did not have the protective CMV IgG antibodies and were in the age range of 16-30 years old. They were also found to be in their second trimester, which could have increased the risk of intrauterine transmission. The risk factors for CMV were observed to have been significantly (P > 0.05) correlated with the socioeconomic status, the levels of CMV Ig-G antibodies, stage of pregnancy as well as the symptoms of pregnancy complications observed in the study population while they were insignificant (P < 0.05) in the case of number of previous pregnancies. The outcome of effects on the fetus was usually fatal and irreversible. Therefore, all pregnant women should scrupulously consistently adhere to routine infection control precautions. Keywords: Cytomegalo virus, Pregnant women, sero-prevalence, Sokoto

    A Study of the androgen receptor gene polymorphism and the level of expression of the androgen receptor in androgenetic alopecia among Egyptians

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    Background: Androgenetic alopecia (AGA) occurs in men and women. Thenature of the genetic predisposition to androgenetic alopecia is still unresolved. The aim of the work is to study the genotype of the androgen receptor gene (StuI polymorphism) and its relationship to AGA in a case control study and to determine the level of androgen receptor expression (AR) in the balding scalp relative to the non-balding scalp area.Subjects and Methods: This study was conducted on one hundred individuals; 60 cases with AGA (36 males and 24 females) and 40 age and sex matched control patients (20 males and 20 females). StuI restriction fragment length polymorphism(RFLP) of exon 1 was detected by PCR based assay using genomic DNA of subjects with AGA and controls. Immunohistochemical detection of the androgen receptor (AR) using antihuman AR antibody was implemented to compare its level in the balding scalp and in the non-balding area in individuals having AGA.Results: Analysis of StuI restriction fragment length polymorphism in exon 1 of the androgen receptor (AR) gene revealed a relatively commoner incidence of the cut allele in males with AGA relative to age and sex matched controls (the association was of border line signifi cance p=0.07. Interestingly, all persons who had maternal uncles suffering from AGA had the Stu1 cut variant of AR gene (p= 0.03 using Chi square test). Semiquantitative immunohistochemical analysis of AR in the bold scalp biopsies showed higher expression in the level of AR than the non bold bioposies within the same individual.Conclusion: To the best of our knowledge this is the fi rst study of AR gene polymorphism and AR expression in AGA amongst Egyptians. This study contributes in the understanding of the molecular pathogenesis of AGA which could help in fi nding better therapeutic alternatives for such trait in the future.Keywords: Androgenetic alopecia, androgen receptor, StuI polymorphism, immunohistochemical expression

    Sterilizing Activity of Second-Line Regimens Containing TMC207 in a Murine Model of Tuberculosis

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    The sterilizing activity of the regimen used to treat multidrug resistant tuberculosis (MDR TB) has not been studied in a mouse model. (TB) strain H37Rv, treated with second-line drug combinations with or without the diarylquinoline TMC207, and then followed without treatment for 3 more months to determine relapse rates (modified Cornell model).Bactericidal efficacy was assessed by quantitative lung colony-forming unit (CFU) counts. Sterilizing efficacy was assessed by measuring bacteriological relapse rates 3 months after the end of treatment.The relapse rate observed after 12 months treatment with the WHO recommended MDR TB regimen (amikacin, ethionamide, pyrazinamide and moxifloxacin) was equivalent to the relapse rate observed after 6 months treatment with the recommended drug susceptible TB regimen (rifampin, isoniazid and pyrazinamide). When TMC207 was added to this MDR TB regimen, the treatment duration needed to reach the same relapse rate dropped to 6 months. A similar relapse rate was also obtained with a 6-month completely oral regimen including TMC207, moxifloxacin and pyrazinamide but excluding both amikacin and ethionamide.In this murine model the duration of the WHO MDR TB treatment could be reduced to 12 months instead of the recommended 18–24 months. The inclusion of TMC207 in the WHO MDR TB treatment regimen has the potential to further shorten the treatment duration and at the same time to simplify treatment by eliminating the need to include an injectable aminoglycoside
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