Secondary Ion Mass Spectrometry and Time-of-Flight Secondary Ion Mass Spectrometry Study of Impurity Measurements in HgCdTe

In this study, time-of-flight (TOF) secondary ion mass spectrometry (SIMS) was compared against dynamic SIMS to determine detection limits and background levels for nine impurities: Li, Na, K, Al, Ni, As, In, Fe, and Cu. Statistics were gathered by measuring six material test structure samples from six different liquid phase epitaxy (LPE) HgCdTe double layer heterojunction (DLHJ) wafers. Also included is a comparison between dynamic SIMS and TOF-SIMS capabilities.     

Crystalline ZnO and ZnO/TiO2 nanoparticles derived from tert-butyl N-(2 mercaptoethyl)carbamatozinc(II) chelate: Electrocatalytic studies for H2 generation in alkaline electrolytes

A newly synthesized zinc(II) complex, namely tert-butyl N-(2 mercaptoethyl)carbamatozinc(II) complex [Zn(Boc-S)₂] (Boc = tert-butyl N-[2-mercaptoethyl]carbamate), has been used as an organozinc precursor for the production of crystalline ZnO and ZnO/TiO₂ nanoparticles. The synthesized complex and the obtained nanomaterials were fully characterized using various spectroscopic and surface analysis techniques. Their surface morphology, chemical purity and stoichiometry have been investigated by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) as well as X-ray fluorescence. The synthesized Zn(II) molecular complex, ZnO and ZnO/TiO₂ nanomaterials have been tested in alkaline aqueous solution (1.0 MNaOH) for the hydrogen evolution reaction (HER) using various electrochemical techniques. The results revealed high HER catalytic performance of ZnO and ZnO/TiO₂ cathode materials, with the latter exhibiting higher catalytic activity recording an exchange current density (j_o) of 0.3 mA cm⁻². This current value, which approaches that of Pt wire (0.5 mA cm⁻²), cross-sectional area ~0.008 cm², is about 11 and 100 times greater than those measured for ZnO alone (0.028 mA cm⁻²) and TiO₂ alone (0.0032 mA cm⁻²), respectively. Moderate catalytic activity was recorded for the complex catalyst, namely GC-Zn(Boc-S)₂ with j_o value of (0.01 mA cm⁻²). Tafel slope values of 130 and 122 mV dec⁻¹ were calculated for ZnO and ZnO/TiO₂, respectively. Such Tafel slope values, which are close to that of the Pt wire (120 mV dec⁻¹), referred to a Volmer-controlled HER kinetics. Other important electrochemical parameters describing the kinetics of the HER, such as roughness factor (R_f) and turnover frequency (TOF) were also estimated and discussed. The high numerical values of the various HER kinetic parameters recorded for the ZnO/TiO₂ catalyst, in addition to its high stability and durability (stable for up to 10 000 continuous cathodic polarization cycles), besides maintaining its morphology and chemical composition after stability test (confirmed from SEM/EDX and XRD examinations), located it in a privileged position among the most efficient HER electrocatalysts reported in the literature.     

Experimental performance of cooling photovoltaic panels using geothermal energy in an arid climate

In this study, an experimental prototype was built to examine the use of an underground water tank as a heat exchange medium with the soil to reduce photovoltaic (PV) panel operation temperatures and simultaneously improve PV efficiency. Three PV systems were evaluated: a benchmark PV panel without cooling (panel A); a PV panel with water spray cooling (panel B); and a PV panel with evaporative cooling (panel C). The cooling techniques in modules (B) and (C) were used to investigate the effects of underground water on the performance of PV panels in arid conditions. Four cases were devised as follows: spray panel back cooling (I), spray front and back cooling (II), spray front and back cooling using an Arduino controller (III), and repeating case III with different water flow rates (IV). Readings were taken from 9:00 am to 4:00 pm  from May to August. The experimental results showed that the use of underground water spray cooling led to reductions in the temperature of PV panel B, 14°C, 17.6°C, 18.8°C, and 22.7°C for cases I, II, III, and IV, respectively, when compared with the uncooled panel, and efficiency improved by 3.5%, 4.8%, 18%, and 23.1%, respectively.     

Nanoemulsions: formation,stability and an account of dietary polyphenol encapsulation

To enhance nutraceutical performance, vehicle systems are required to promote the usage of food supplements, which have shown an increasingly growing demand. These food supplements such as dietary polyphenols are nutritious constituents but with varying solubility, sensitivity to oxygen, light, temperature, or adverse effects encountered during processing, making their incorporation difficult in foods. Additionally, these are bound to the food matrix so tightly, that they are not available to be taken up in the digestive system causing less absorption in the gastrointestinal tract. To counter these challenges, polyphenols are encapsulated in nanoemulsion-based delivery systems which forms an effective approach to enhance and improve their bioavailability. Because of their small droplet size, these exhibit various benefits over conventional emulsions making them suitable for usage in the food industry. This review summarises the basic characteristics of nanoemulsions and their application to enhance the stability of polyphenols.     

Significant association of a single nucleotide polymorphism in the upstream region of FGFR1OP2/wit3.0 gene with residual ridge resorption of mandible in Saudis

Residual ridge resorption (RRR) is the decrease in the jaw structure that follows tooth extraction. It is amultifactorial disorder, but reports on the associated genetic factors are scarce, particularly amongst the Saudis. Thisstudy aimed to investigate the role of single nucleotide polymorphisms (SNPs) in fibroblast growth factor receptor1 oncogene partner 2 (FGFR1OP2) in RRR development in Saudis. The study included 192 individuals (RRR = 96;controls = 96) attending outpatient clinics at the College of Dentistry, King Saud University. Demographic and clinicaldata were collected, the digital panoramic dental radiograph was obtained, and mandibular residual ridge heightwas measured. DNA was extracted from saliva and genotyping was conducted on “Sequenom MassARRAY iPLEX”.Genotype and allele frequencies of three SNPs were calculated and compared. The age at first diagnosis and bone heightwere compared in the three genotypes of each SNP. The age of the patients, age at first edentulism, and bone heightranged 21-80 years, 12-70 years, and 13-34.6 mm, respectively. All three genotypes of the studied SNPs (rs2279351,rs78054962 and rs2306852) were identified. SNP rs2279351 associated significantly with RRR, and the mutant Callele was highly predisposing. No association was observed for the other two SNPs. The genotypes of all SNPs had aninfluence on age at first edentulism and bone height, but the results were not statistically different. Since FGFR1OP2plays a role in the process of rapid wound healing in the oral cavity, it may be playing a role in the development ofRRR by influencing the rate of resorption of the jawbone. SNP rs2279351 may alter its expression and hence RRRdevelopment. This study is limited due to small a sample size, and further large-scale studies are required to confirmthis association and to consider rs2279351 as a possible marker of RRR development.     

Predicting and reducing “hospital-acquired infections” using a knowledge-based e-surveillance system

The use of automated computer methods when detecting hospital-acquired infections (HAIs) enhances the validity of the surveillance in an effective manner. This is because manual infection control systems used by hospitals are time consuming and are often restricted to intensive care units. This paper proposes a new knowledge-based electronic surveillance system to predict and reduce HAIs. The system can gather patient-associated data from hospital databanks to automatically predict patient injury based on the standard central line-associated bloodstream infection algorithm for HAI detection rules. The application of the proposed electronic system reduces the number of central lines associated with infection of the bloodstream and reduces the length of stay for patient treatment and thus reduces costs. The proposed system has several advantages: (a) It is a web-based system that collects actual data from patients from several IT sources, which will help collect patient data safely and quickly, thereby predicting HAIs effectively. (b) It has an integrated simulator to generate patient records, providing the ability to train medical personnel and nurses to enhance their skills. (c) It is a multimedia-based system to improve patient health reporting. (d) It assists policymakers in reviewing and approving control plans and policies to reduce and prevent hospital injuries. (e) The investigational results of the system showed an enhancement value equal to 87%.