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Audio applications such as mobile phones, hearing aids, true wireless stereo earphones, and Internet of Things devices demand small size, high performance, and reduced cost. Microelectromechanical system (MEMS) capacitive microphones fulfill these requirements with improved reliability and specifications related to sensitivity, signal-to-noise ratio (SNR), distortion, and dynamic range when compared to their electret condenser microphone counterparts. We present the design and modeling of a semiconstrained polysilicon diaphragm with flexible springs that are simply supported under bias voltage with a center and eight peripheral protrusions extending from the backplate. The flexible springs attached to the diaphragm reduce the residual film stress effect more effectively compared to constrained diaphragms. The center and peripheral protrusions from the backplate further increase the effective area, linearity, and sensitivity of the diaphragm when the diaphragm engages with these protrusions under an applied bias voltage. Finite element modeling approaches have been implemented to estimate deflection, compliance, and resonance. We report an 85% increase in the effective area of the diaphragm in this configuration with respect to a constrained diaphragm and a 48% increase with respect to a simply supported diaphragm without the center protrusion. Under the applied bias, the effective area further increases by an additional 15% as compared to the unbiased diaphragm effective area. A lumped element model has been also developed to predict the mechanical and electrical behavior of the microphone. With an applied bias, the microphone has a sensitivity of −38 dB (ref. 1 V/Pa at 1 kHz) and an SNR of 67 dBA measured in a 3.25 mm × 1.9 mm × 0.9 mm package including an analog ASIC.

Background Blood and oral fluid-based HIV self-tests are important for reaching the undiagnosed living with HIV. The study objectives were to evaluate the oral fluid-based OraQuick® HIV Self-Test (HIV-ST) performance in comparison to laboratory reference testing; determine if laypersons can correctly perform the HIV-ST; document if intended users can successfully interpret pre-made contrived positive, negative, and invalid results; and document if intended users can understand the key messages in the product labeling. Methods This prospective study enrolled consenting adult intended users of HIV self-testing from six community health centres in four Canadian provinces between June 2022 and January 2024. Positive and negative agreement was determined by comparing the results of the HIV self-tests with the results of the laboratory-based “gold standard” Abbott Alinity HIV Antigen/Antibody Combo test. Descriptive statistics were used to summarize usability self-test procedure steps. Results Overall, 951 participants were recruited and consented with 911 available for all analyses. With respect to sociodemographics: 84% of participants were between 18–45 years of age, 73% had at least a college education, 48% were Cis-male, 45% were employed; and 26% identified as White, 23% as African, Caribbean or Black, 5% as Indigenous [First Nations, Métis or Inuit], 33% as Asian, and 6% as LatinX. Primary efficacy analysis on the 911 who completed HIV-ST revealed a single confirmed positive participant and a negative percent agreement of 100% (880/880, 95% CI: 99.9–100%) with the comparator method. For usability determination, the average success rate for “critical” steps for completing the test was 94.1%. Approximately 97% of participants found the instructions easy to follow and 98% of participants reported they would use the test again. Of the 465 participants who interpreted the strong positive, weak positive, negative, and invalid pre-made contrived results, the average of correct interpretations ranged from 59–97% Conclusions A licensed oral fluid-based HIV self-test in Canada can present an accurate, easy-to-use, and less invasive alternative to blood-based HIV testing. The addition of an oral-fluid self-test along with the current licensed blood-based HIV self-test could help reach the undiagnosed with HIV in Canada and positively impact HIV testing rates overall by offering individuals a choice of self-testing devices.

The efficiency of the electrocoagulation method to remove boron from synthetic and mining effluents was investigated in this study. Different parameters were tested using boric acid solution and effluent collected from a mining company located in the city of Vitória-ES. The results showed a percentage of boron removal of over 60% for the synthetic and mining effluents, using aluminum electrodes, pH 7.5, current density of 14.82 mA cm−2, and supporting electrolyte of 0.200 mol L−1. The electrocoagulation and chemical coagulation methods were also compared, in which the percentage obtained by electrocoagulation was 56.30% higher for the mining effluent. Thus, electrocoagulation was more efficient in boron removal, especially when appropriate parameters are applied.

Background Self testing for HIV is a targeted intervention with the potential to increase the access, uptake and frequency of HIV testing and more effectively reach the undiagnosed, especially in priority populations. The objectives of this study were to (1) evaluate the INSTI HIV self-test performance compared with laboratory reference testing, (2) document if intended users can perform the steps to use the HIV self-test device, and (3) document if intended users can successfully interpret contrived positive, negative, and invalid results. Study was intended to be submitted to Health Canada for review for regulatory approval purposes. Methods The study used a cross-sectional design and recruited consenting adults who were representative of intended users of HIV self-testing from four community sites across Ontario, Québec, and Manitoba between August 2019 and March 2020. The results of the observed HIV self-test were compared with results of the Abbott Architect HIV Ag/Ab Combo test. Usability outcomes for critical (e.g., lancing finger, blood droplet into bottle, shaking bottle four times) and noncritical self-test procedure steps were also determined. Results Overall, 77% ( n  = 522) of participants were between 18 and 45 years of age, 61% ( n  = 410) were male, 71% ( n  = 480) had some college or more education, and 45% ( n  = 307) were employed; identity for race and ethnicity: Caucasian (44%; n  = 296), African, Caribbean or Black (17%; n  = 113), Indigenous [First Nations, Métis or Inuit] (14%; n  = 95), Asian (16%; n  = 106), Latin American (7%; n  = 46). Primary performance analysis on 678 completed HIV self-tests revealed a positive percent agreement of 100% (5/5, 95% CI: 43.6–97.0%) and a negative percent agreement of 99.5% (614/617, 95% CI: 98.6–99.8%) with the comparator method. The overall percent agreement of results interpretation between participant and observer was 93.5% ( n  = 633). For the 708 participants who took part in the usability study, the average success rate for steps determined to be “critical” for successful completion of the test was 92.4%. 97% ( n  = 670) of participants found the instructions easy to follow, and 95% ( n  = 655) of participants indicated that they would use the test again. Of the 404 participants who interpreted the strong positive, weak positive, negative, and invalid contrived results, successful interpretation ranged from 90.6% (for weak positive, n  = 366) to 99.3% (for negative, n  = 401). Conclusions The addition of a regulatory-approved self-test into the Canadian HIV testing landscape could significantly increase HIV testing rates. Having a blood-based HIV self-test approved in Canada can offer an accurate, acceptable, and simple alternative to facility-based HIV testing, particularly when impacted by Coronavirus pandemic restrictions.

Streptococcus pneumoniae is the commonest cause of bacteremic pneumonia among HIV-infected persons. As more countries with high HIV prevalence are implementing infant pneumococcal conjugate vaccine (PCV) programs, we aimed to describe the baseline clinical characteristics of adult invasive pneumococcal disease (IPD) in the pre-PCV era in South Africa in order to interpret potential indirect effects following vaccine use. National, active, laboratory-based surveillance for IPD was conducted in South Africa from 1 January 2003 through 31 December 2008. At 25 enhanced surveillance (ES) hospital sites, clinical data, including HIV serostatus, were collected from IPD patients ≥ 5 years of age. We compared the clinical characteristics of individuals with IPD in those HIV-infected and -uninfected using multivariable analysis. PCV was introduced into the routine South African Expanded Program on Immunization (EPI) in 2009. In South Africa, from 2003-2008, 17 604 cases of IPD occurred amongst persons ≥ 5 years of age, with an average incidence of 7 cases per 100 000 person-years. Against a national HIV-prevalence of 18%, 89% (4190/4734) of IPD patients from ES sites were HIV-infected. IPD incidence in HIV-infected individuals is 43 times higher than in HIV-uninfected persons (52 per 100 000 vs. 1.2 per 100 000), with a peak in the HIV-infected elderly population of 237 per 100 000 persons. Most HIV-infected individuals presented with bacteremia (74%, 3 091/4 190). HIV-uninfected individuals were older; and had more chronic conditions (excluding HIV) than HIV-infected persons (39% (210/544) vs. 19% (790/4190), p<0.001). During the pre-PCV immunization era in South Africa, 71% of serotypes amongst HIV-infected persons were covered by PCV13 vs. 73% amongst HIV-uninfected persons, p = 0.4, OR 0.9 (CI 0.7-1.1). Seventy to eighty-five percent of adult IPD in the pre-PCV era were vaccine serotypes and 93% of cases had recognized risk factors (including HIV-infection) for pneumococcal vaccination. These data describe the epidemiology of IPD amongst HIV-infected and -uninfected adults during the pre-PCV era and provide a robust baseline to calculate the indirect effect of PCV in future studies.

Low-volume microelectromechanical systems (MEMSmicroelectromechanical system (MEMS))/nanoelectromechanical systems (NEMSnanoelectromechanical system (NEMS)) production is practical when an attractive concept is implemented with business, manufacturing, packaging, and test support. Moving beyond this to high-volume production adds requirements on design, process control, quality, product stability, market size, market maturity, internal capacity, and capital investment or transfer to foundry and business systems. In a broad sense, this chapter uses a case study approach: It describes and compares the silicon-based MEMS accelerometers and gyroscopes that are in high-volume production. What is described here also applies to other MEMS products such as pressure sensors, image projection systems, microphones, etc. Although they serve several markets, these businesses have common characteristics. For example, the manufacturing lines use automated semiconductor equipment and standard material sets to make consistent products in large quantities. Standard well-controlled processes are sometimes modified for a MEMS product. However, novel processes that cannot run with standard equipment and material sets are avoided when possible. When transferring to an external foundry, existing processes are modified to utilize the foundry equipment and processes where possible. This reliance on semiconductor tools, as well as the organizational practices required to manufacture clean, particle-free products, partially explains why the MEMS market leaders are integrated circuit manufacturers. There are other factors. MEMS and NEMS are enabling technologies, so it can take several years for high-volume applications to develop. Indeed, market size is usually a strong function of price. This becomes a vicious circle, because low price requires low cost – a result that is normally achieved only after a product is in high-volume production. During the early years, IC companies reduce cost and financial risk by using existing facilities for low-volume MEMS production. As a result, product architectures are partially determined by capabilities developed for previous products. This chapter includes a discussion of MEMS product architecture with particular attention to the impact of electronic integration, packaging, and surfaces. Packaging and testing are critical, because they are significant factors in MEMS product cost. MEMS devices have extremely high surface-to-volume ratio, so performance and stability may depend on the control of surface characteristics after packaging. Looking into the future, the competitive advantage of IC suppliers is decreasing because MEMS foundries are growing and small companies are learning to integrate MEMS/NEMS devices with die from CMOS foundries in one package. Packaging challenges still remain, because most MEMS/NEMS products must interact with the environment without degrading stability or reliability.

The finite viscoplastic deformations of porous metals are examined in order to gain insight into the mechanisms involved in the working of porous preforms. It is assumed that the primary microstructural parameters that influence the behavior of porous metals are the porosity (pore volume fraction) and the pore shape (aspect ratio). The metals chosen for this study are a common titanium alloy (Ti-6Al-4V) and pure iron. Preliminary work was performed on the titanium alloy with 8% residual porosity. The fully dense titanium alloy was subject to specific heat treatment such that the final microstructural features were similar to those of the matrix in the porous metal. However, the effort had limited success, because the Ti-6Al-4V alloy system is quite complicated and because the monolithic alloy and the porous metal had two different processing histories. This led to shifting from this alloy system to single phase pure iron as the matrix metal. Pure iron powders are compacted at various pressures, sintered and annealed to obtain samples covering a wide range of porosity, from 30% to near full density. The monolithic metal samples as well as the porous metal at various initial porosities are tested (at room temperature) in uniaxial quasistatic (10 $\\sp{-4} - 10\\sp{-2}\\ s\\sp{-1})$compression as well as under dynamic conditions ( $10\\sp2 - 7 \\times 10\\sp3\\ s\\sp{-1})$using a compression Kolsky bar. The axial inelastic strain is also varied from about 5% to 35%. This enables us to obtain a constitutive description for the porous material (in compression) from the experimental data. A combination of direct density measurements as well as optical radial strain measurements are used to track the volume change (compaction) in the porous metal. Utilizing the above experimental results a general rate dependent viscoplastic model for isotropic porous metals undergoing finite deformations is formulated. The constitutive framework incorporates the dependence on the pore volume fraction and the pore shape (aspect ratio), both of which evolve as the deformation proceeds. However, for purposes of this work we restrict our study to just the influence of the pore volume fraction on the behavior of porous metals. The results from the model (for the case when the porosity is constrained to remain spherical) are observed to be in good agreement with the experimental results.

Mohamed Ayjaz, of Hamptons International Oman, says: 'Oman offers an alternative to the normal Arabian identity, whether it's unparalleled scenic beauty, architectural or cultural perspective. Self-reliance and pride in cultural origin are prevalent in all aspects of life here.' With a population of approximately 2.3 million, Oman is being modernised and liberalised culturally and financially by hereditary Sultan, Qaboos Bin Said Al-Said. He's a forward-thinking ruler, who is actively trying to diversify the country's economy and its reliance on diminishing oil reserves. 'The introduction of ITCs was one of the key ingredients for planned growth in tourism levels,' says Christopher Steel, of Savills Oman. The Omani market offers a low-risk strategy for homeowners and wise property investors seeking a safe haven.' Steel, who refers to Oman as the 'Switzerland of the Middle East', reports that around 70 per cent of all people buying homes in ITCs are foreigners, mostly from the Indian subcontinent, Germany, Scandinavia and Britain. [Matthew Wright] says: 'Oman has not developed as rapidly as its neighbours in the UAE and has relatively few developments available for purchase by non-GCC nationals in comparison to Abu Dhabi and Dubai.' New luxurious ITCs under construction across Oman include The Wave, The Chedi, Azaiba, Wadi Kabi, Salalah Beach Resort, Barr Al-Jissah, Yiti Resort, Muscat Hills Golf & Country Club, Blue City, Jebel Sifah and The Malkai.

Pantelis Leptos, of Leptos Estates, reports that fewer than 200,000 homes were sold in 2009, compared to 600,000-plus in 2008. The government in Belize, an independent member of the British Commonwealth, doesn't charge residents capital gains, inheritance or income tax on overseas earnings and assets. income tax, starting at 15 per cent, is charged only on money earned in Belize. there are no restrictions on foreigners owning a freehold title. Leptos estates: 020 8883 2333, leptosestates.com. Andorra-property.com: 00376 737 900. Chesterton Humberts estate agents: 0203 040 8210, chestertonhumberts.com.