233 research outputs found
Experience curve models in technology cost forecasting:The case of solar Photovoltaic modules
Electrical power generation from residual biomass by combustion in externally fired gas turbines (EFGT)
The rising interest in developing gas turbines make it important to investigate them in energy generation from solid biomass. Addiotionally, externally fired gas turbine plant has the advantage of solid fuel flexibility. Pressure and air mass flow through the clean cycle side are optimized to provide the maximum power. Hardware-in-the-loop (HiL) is integrated beside the real combustion process. It serves in being more flexible in tuning plant parameters for several values, for instance, heat exchanger design, compressor and turbine efficiencies, and pressure and mass flow values
Risk of perinatal transmission of hepatitis B virus in Jordan.
OBJECTIVES: To determine the risk of perinatal transmission of hepatitis B virus (HBV) in Jordan. METHODS: Plasma samples from 1000 pregnant Jordanian women were screened by ELISA for HBV markers (HBsAg, HBeAg, anti-HBe, anti-HBc and anti-HBs). RESULTS: HBsAg and HBeAg were detected in 4.3% and 0.1% of the pregnant women, respectively. The overall prevalence of antibodies was 6%, 11.1% and 7.5% for anti-HBe, anti-HBc and anti-HBs, respectively. Women were assigned to four groups according to the serological patterns of HBV markers: susceptible (85.9%), with acute infection (2.9%), with chronic infection (1.4%) and previously infected (9.8%). Most women were at the third trimester of pregnancy, therefore women with acute and chronic hepatitis at this gestational age were at risk of transmitting HBV infection to their newborns. Women who belonged to the low socio-economic class were at higher risk of HBV infection. CONCLUSIONS: Based on the results, we recommend screening women for HBV during pregnancy in order to identify HBV carriers. All newborns born to carriers should be vaccinated immediately after birth, both passively and actively. Also vaccination of HBV seronegative pregnant women is recommended
A Human Body Mathematical Model Biometric Using Golden Ratio: A New Algorithm
This research provides more than 35 measurements rules derived from the perspectives of Vitruvian Man and Neufert and their basis of the golden proportion, to build a human body model on computers for the use of multimedia. The measurements are based on 25 proportional rules derived from 15 proportions given by Vitruvian Man and 29 golden proportions in Bauentwurfslehre by Ernst Neufert. Furthermore, the research will suggest two algorithms to calculate the 67 measurements with precision; assuming that the algorithms output will be used as guideline to human body modelers in simulation, gaming, plastic surgery, as well as the world of biometrics or wherever human body measurements and calculations is needed like prosthetic limbs, spatial design, and machine learning of human biometrics. Furthermore, building proportional models creates visual harmony in measurements and visual parity model. Hence, the chapter facilitates and explains for the human modeler the process of human modeling from within an algorithm. This research is an expanded work based on two published conference papers listed in the references section
Innovative Application of Scrap-tire Steel Cords in Concrete Mixes
More than 2.5 million scrap-tires are produced in Jordan each year. In addition, more than three million tires are currently stockpiled throughout the country. However, only one company has been established in the country for the recycling, recovery and reuse of scrap-tires. Currently, this industry is facing many challenges due to lack of support and subsidies from the government. Many researchers have investigated the use of recycled tire products in several traditional civil engineering materials. This research is exploring the use of steel cords, a by product of the tire recycling process, in concrete mixes. Different concrete specimens were fabricated and tested in uniaxial compression and splitting tensile strength. The steel cords were substituted into the concrete mix in volumetric percentages of 0% (control), 2%, 4%, 6%, 8% and 10%. Results show that mechanical properties of concrete made with steel cords are improved compared with concrete mix made with the traditional scrap-tires recycled material (such as crump rubber or rubber chips). Also, the test results show that even though the compressive strength is reduced when using steel cords, this reduction is minimal. When 2% of steel cords are used, there is an 18% increase in ductility. Moreover, splitting tensile tests show that concrete mixtures with any steel cords content have much greater toughness than the control mixture. This mechanical property mix indicates an excellent potential application of modified concrete mix in structures that absorb large amounts of energy. On the contrary, the density, air content and workability of the mixtures fabricated were not significantly affected
Characterization of the Functional Domains of the Herpes Simplex Virus (HSV-2) Strain HG52 RL1 Gene
The long repeat region of HSV-1 contains the diploid RL1 gene which encodes the protein ICP34.5, a 43K polypeptide of 263 amino acids in HSV-1 strain F and a 37K polypeptide of 248 amino acids in HSV-1 strain 17+ infected cells. The role of RL1 in virulence of HSV-1 has been studied by Chou et al (1990), MacLean, A et al (1991) and McKie et al (1994). The discovery of the RL1 gene in HSV-1 was followed by sequencing data of the corresponding region of HSV-2 strain HG52 which indicated that HG52 possesses a counterpart of the HSV-1 RL1 gene (McGeoch et al., 1991). The organization of HG52 RL1 differs from that of HSV-1 although both initiation codons are in equivalent positions. The coding sequence of HG52 RL1 lacks the (PAT)io repeat element and is disrupted by a reiterated sequence proposed to be an intron. Removal of this intron results in a second exon containing a 63-amino acids HSV-l/HSV-2 conserved region, being in frame. To characterise the functional domains of the HSV-2 RL1 gene, three mutant viruses have been constructed and characterized: (1) 2620, with a stop codon within the conserved region, 46 amino acids upstream of the 3' end of RL1 (2) 2621, with an in frame stop codon 9bp downstream of the initiating ATG and (3) 2622, in which the proposed intron has been apparently deleted. The mutant viruses 2620, 2621 and 2622 were characterized in vivo following intracerebral inoculation of Balb/c mice and in vitro using BHK21/C13 and 3T6 mouse embryo fibroblast cells. The mutant 2621 was avirulent with a LD50 >107 p.f.u./mouse compared to 3.16x106 p.f.u./mouse for 2604 and 102 p.f.u./mouse for HG52. The 2620 mutant was also avirulent with a LD50 of 2.37x106 p.f.u./mouse. The 2622 mutant was intermediate with a LD50 of 105 p.f.u./mouse. The growth of the mutants 2620 and 2621 was not impaired in BHK21/C13 but was impaired in 3T6 cells. The growth of 2622 was comparable to that of the wild-type HG52 in BHK21/C13 cells and intermediate between HG52 and the avirulent deletion mutant 2604 in 3T6 cells. Rescuants of the mutants (R2620, R2621, R2622) were generated by in vitro and in vivo marker rescue. Those generated by in vitro marker rescue demonstrated an intermediate virulence phenotype. Rescuants, generated by in vivo marker rescue, except for R2620 were restored to the full virulence phenotype of the wild-type HG52 pi. 17. A secondary mutation in the genome of 2620 and its rescuants generated by in vitro marker rescue could explain failure of the R2620 rescuants to return to wild-type virulence. The secondary mutation could be due to passage of the virus during purification and/or virulence heterogeneity within the HG52 pi. 17 stock. Individual plaques of HG52 pi. 17 demonstrated variable virulence phenotypes. The rescuants generated in vitro and individual plaques of HG52 pi. 17 were characterised by growth in 3T6 cells which differentiates between ICP34.5 positive and negative virus. The 3T6 growth and plaque morphology strongly discount a possible mutation in RL1 which should be confirmed when an antiserum against ICP34.5 of HG52 becomes available. It seems that the growth phenotype of HG52 variants in vitro does not always mimic the in vivo phenotype thus emphasising the necessity of the animal model to determine virulence. The demonstrated heterogeneity of the HG52 pl. 17 stock emphasises the necessity of in vivo marker rescue experiments to confirm the phenotype of constructed mutants
The impact of social media use on mental health and family functioning within web-based communities in Saudi Arabia: ethnographic correlational study
Background:Â In recent years, increasing numbers of parents, activists, and decision-makers have raised concerns about the potential adverse effects of social media use on both mental health and family functioning. Although some studies have indicated associations between social media use and negative mental health outcomes, others have found no evidence of mental health harm.
Objective: This correlation study investigated the interplay between social media use, mental health, and family functioning. Analyzing data from 314 users, this study explores diverse mental health outcomes. The study places particular emphasis on the Saudi Arabian sample, providing valuable insights into the cultural context and shedding light on the specific dynamics of social media’s impact on mental well-being and family dynamics in this demographic context.
Methods: We collected data through a subsection of an anonymous web-based survey titled “The Effect of COVID-19 on Social Media Usage, Mental Health, and Family Functioning.” The survey was distributed through diverse web-based platforms in Saudi Arabia, emphasizing the Saudi sample. The participants indicated their social media accounts and estimated their daily use. Mental health was assessed using the General Health Questionnaire and family functioning was evaluated using the Family Assessment Device Questionnaire. In addition, 6 mental health conditions (anxiety, self-esteem, depression, body dysmorphia, social media addiction, and eating disorders) were self-reported by participants.
Results:Â The study demonstrates a pattern of frequent social media use, with a significant portion dedicating 3-5 hours daily for web-based activities, and most of the sample accessed platforms multiple times a day. Despite concerns about social media addiction and perceived unhealthiness, participants cited staying connected with friends and family as their primary motivation for social media use. WhatsApp was perceived as the most positively impactful, whereas TikTok was considered the most negative for our Saudi sample. YouTube, Instagram, and Snapchat users reported poorer mental health compared with nonusers of these platforms. Mental health effects encompassed anxiety and addiction, with age and gender emerging as significant factors. Associations between social media use and family functioning were evident, with higher social media quartiles correlating with a greater likelihood of mental health and unhealthy family functioning. Logistic regression identified age and gender as factors linked to affected mental health, particularly noting that female participants aged 25-34 years were found to be more susceptible to affected mental health. In addition, multivariable analysis identified age and social media use quartiles as factors associated with poor family functioning.
Conclusions:Â This study examined how social media affects mental health and family functioning in Saudi Arabia. These findings underscore the need for culturally tailored interventions to address these challenges, considering diverse demographic needs. Recognizing these nuances can guide the development of interventions to promote digital well-being, acknowledging the importance of familial connections in Saudi society
Assessment of Infectious Waste Management Practices at Hospital with Excellent Accreditation Level in Bandung, Cimahi and East Jakarta, Indonesia
This study includes the procedures available and methods of handling and disposing of infectious waste at Military hospital with Excellent Accreditation level in Bandung, Cimahi and East Jakarta, Indonesia. A total three (3) military hospitals with equal type of hospital and level accreditation were surveyed during the course of this research. The methods consisted of survey and interview with the authorities of the hospital and the personal involved in the management of the generated waste. The information was collected using forms specially developed for this purpose. Site visits were conducted to support and supplement information gathered in the survey. Assessment of infectious waste handling divided into six parameters: Hospital policy at organizational structure, status of cleaning services worker, classification/segregation process, collect and transport the infectious waste, condition of temporary storage of infectious waste and disposal phase of infectious waste. The result showed that the hospital with highest level of accreditation have less appropriate practices when it comes to segregation, collecting, storage and disposal of waste generated in comparison to developed country. It appears that hospital authorities should pay better attention to educational planning, organizational resources and supervision at infectious waste management
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