Pulse Density Modulation Applied to Series Resonant Inverter and Ac‐Ac Conversion

The PDM control joins together between the concepts of soft switching and hard switching. Its application to the series resonant inverter cancels the switching losses and uses dc bus without storage capacity. Objectively, the PDM controls led to ac‐ac converters with high efficiency (zero switching loss), small size (no storage capacity) and with the possibility of a self power factor correction. However, the operating analysis of these converters is very complex because the operation is done on two time scales and leaves questions unanswered. The average modeling facilitates the analysis of the operation and leads to establish: (i) an analytical expression of the power factor, (ii) the linearity conditions of the power characteristic, and (iii) a model of ac‐ac series resonant multi‐converter which is independent of the carriers. In the case of ac‐ac series resonant multi‐converter, the coordination of carriers allows to shape the power characteristic. Among the three types of coordination presented, there is an original coordinate that linearizes the power characteristic. The results are validated by simulations carried out in Matlab SimPower systems

Treatment of Primary Settled Wastewater Using Anaerobic Sequencing Batch Reactor Seeded with Activated EM

The biologic treatment process using effective microorganisms (EM) in an anaerobic sequencing batch reactor (ASBR) for primary settled wastewater treatment was investigated. Activated EM was formed from raw EM to increase its efficiency by ensuring that the microorganisms were in an exponential phase of growth. A bench-scale ASBR (volume 2.6 l) was seeded with activated EM and the characteristics of the influent and effluent wastewater were investigated under different temperatures and reaction times. This system achieved good removal efficiency for all the analyzed parameters. The removal efficiency of the chemical oxygen demand (COD), soluble COD, biochemical oxygen demand, total suspended solids, ammonia, and total phosphorus increased with increasing reaction time and temperature, and reached 72.1%, 61.5%, 75.7%, 80.9%, 50.4%, and 62.5% respectively, at a reaction time of 24 h and at 35 °C. The system showed good removal of total coliform and salmonella and a reduction in ammonia and sulfate-reducing bacteria. Biogas can also be obtained using this system. Keywords: Anaerobic treatment; ASBR; Effective microorganisms; Pathogens; Wastewater treatmen

Early and delayed suture adjustments after adjustable suture strabismus surgery: a randomized controlled trial

Background: Adjustable sutures increase the success rate of strabismus surgery. However, the optimal timing of postoperative suture adjustment remains controversial. This trial was aimed at comparing the surgical outcomes and pain scores of early or 2 – 4 h and delayed or 24 h postoperative suture adjustment in adult patients undergoing strabismus surgery. Methods: An open-label, prospective, randomized, comparative interventional study was performed in consecutive adult patients scheduled for eye muscle surgery. Patients were randomized into two groups: the early group, with suture adjustment 2 – 4 h postoperatively, and the delayed group, with suture adjustment 24 h postoperatively. Subjective pain scores during the adjustment were also analyzed. The angles of misalignment at 1 and 3 months and the success rate at 3 months postoperatively were compared. Results: Forty-five (90%) patients completed the follow-up, including 23 (92%) in the early adjustment group and 22 (88%) in the delayed adjustment group, with a mean (standard deviation) age of 25.6 (9.5) years and a male-to-female ratio of 46.7:53.3. Thirty patients (66.7%) had exotropia, and 15 (33.3%) patients had esotropia. Both groups had comparable baseline characteristics (all P > 0.05). The mean pain scores during adjustment did not differ significantly between groups (P > 0.05). The postoperative angles of alignment were comparable between the groups before suture adjustment and at the 1- and 3-month follow-ups (all P > 0.05). The success rate in the early adjustment group was slightly higher (87.0% versus 63.6%), but the difference was not statistically significant (P > 0.05). The success rate was comparable between the groups in patients with esotropia or exotropia (both P > 0.05). Conclusions: Although the early adjustment group had a slightly higher success rate, the difference was not significant. Both groups had comparable subjective pain scores during adjustment. Future clinical trials should be performed different time intervals for postoperative suture adjustment, and subjective and objective outcomes, such as diplopia and stereopsis, should be compared between patients with a first strabismus surgery and those who underwent reoperation. This could better resolve the persistent controversy related to the optimal time for suture adjustment

Determination of carbendazim residues in Moroccan tomato samples using local enzyme-linked immunosorbent assay and comparison with liquid chromatography

The fungicide carbendazim (CBZ) is not approved for agricultural uses in some countries but is still used by many farmers due to its effectiveness. For this reason, in previous work of the same authors, they developed a competitive enzyme immunoassay (ELISA) using rabbit polyclonal antibodies to detect CBZ. This study aimed to validate this in-house ELISA after extraction with methanol for CBZ analysis in tomato samples, and the results were compared with the conventional high-performance liquid chromatography (HPLC) method after QuEChERS extraction. The results showed that both ELISA and HPLC methods have good repeatability, reproducibility and high precision with a good variation verified by principal components analysis (PCA). ANOVA tested the detection limit (LOD), and quantification limit (LOQ), and the values for ELISA (LOD = 0.026± 0.001 µg/L and LOQ = 0.083 ± 0.003 µg/L) were significantly lower than those obtained by HPLC (LOD = 0.61 ± 0.02 µg/L and LOQ = 1.85 ± 0.07 µg/L). ELISA and HPLC were used for analyzing CBZ in 100 Moroccan tomato samples. These two methods detected the presence of CBZ above the Maximum Residue Limit (MRL) level in 9 samples. However, the presence of the  CBZ was detected in the 79 samples by ELISA and quantified in 66 samples. In contrast, the presence of CBZ was detected in 57 and quantified in 35 samples by HPLC. These results showed that the ELISA system coupled with a simple methanol extraction is much more sensitive than HPLC after QuEChERS extraction

Not Our Land: An Analysis of a Socially Dysfunctional Community in El Fayrouz, Red Sea Region, Egypt

Community is an integral part of human social fabric; without a sense of belonging societies can no longer function properly. This paper investigates a low income residential area in El Fayrouz, an area located between the city of Hurghada and El Gouna in the Red Sea Governorate of Egypt. The methodological process of urban analysis is focused on understanding the residents of the area, their behaviours, challenges and expectations through studying qualitative and quantitative social and contextual data. The literature review, analysing similar case studies and benchmarks inspired the proposed solution. It is evident that the diversity of cultures of the migrants coming from Upper Egypt in search for economic opportunities hasformed social segregation in the area. This is magnified by the infrastructure deficiencies, the urban fabric and the unstable sources of income. “Not Our Land”, a manifestation of the sense of isolation and the disregard for the communal space is visualised through the solid waste in the street. This presents anopportunity for an environmental entrepreneurship model which integrates the community through an economic incentive: a solution that encompasses social, economic, ecological and infrastructural dimensions

Business of love: exploring motivations to use and sentiments towards online dating using big data analytics

Online Dating has increased in popularity over the past few years. With the evolution of technology and the internet’s increasing capabilities of interaction, online dating has altered the dating world and offered a convenient, fast, and trendy way to find a partner. In fact, it has yielded an industry that has been growing at a quick pace of 5.3% yearly and was estimated to reach $3 billion of revenues in the US only in 2016, generated by hundreds of online dating businesses. However, both big and small players in the multi-billion dollar industry compete to bring in as many subscribers as they can, using various state-of the-art technologies which are the key to their success. To stay ahead of the competition, in-depth knowledge of consumers is an irreplaceable factor. Adopting the “Uses and Gratifications” approach, the aim of this paper is to boost the knowledge of businesses operating in the field by shedding light on the primary motivations of online daters. It also examines the user experience by identifying sentiments toward dating platforms and finds more insights regarding the causes behind those sentiments. A large set of reviews publicly posted by users was employed as the source of data. The study carried out on 1346 reviews about 47 dating platforms has revealed six primary motivations for using online dating. People surf dating sites to seek love or a serious relationship, meet new people, engage in casual relationships, utilize the convenience offered through virtual dating, follow the trend of meeting others via dating sites, or to validate their personal image which in return provides self-satisfaction to the dater. Among all, the first motivation appeared to be the strongest. The employed text analytics tools named SAS VA and Microsoft Power BI have shown positive, average, and negative sentiments across users towards online dating businesses. Of these, the larger group of users expressed negative sentiment. The study demonstrated that the negative experience was mainly attributed to gaps in the offered services, technology, and quality of other subscribers

Making Connection with Students in the First Year Seminar

This paper discusses engagement tools for cultivating students’ collaborative experiences and accessing faculty through an effective online learning environment. One of the primary goals of the First Year Seminar (FYS) courses for the business discipline is student retention. Students in their first year must overcome many obstacles to succeed academically, and faculty at LaGuardia Community College (LAGCC) need to be able to address these needs so that they can graduate on time. Thus, the Business and Technology (BAT) Department at LAGCC provides the opportunity to use collaborative online tools such as Connect To Completion (C2C) and ePortfolio simultaneously to meet these needs while helping them understand the importance of timely graduation. Faculty in the FYS courses use the virtual advising tool C2C to communicate with their students about various needs, while the ePortfolio serves as a tool that influences student learning

Low-Level Laser Therapy for Diabetic Dermopathy in Patients With Type 2 Diabetes: A Placebo-Controlled Pilot Study

Introduction: Diabetic dermopathy (DD) is the most common cutaneous diabetes marker. Few studies have targeted DD using low-level laser therapy (LLLT). This pilot study aimed to evaluate the effect of LLLT on DD in patients with type 2 diabetes (T2D).Methods: 12 patients with T2D (9 men, 3 women) and bilateral DD were enrolled in this placebo-controlled pilot study, and their ages ranged 50-65 years. One side was subjected to LLLT, three sessions weekly for one month (LLLT side), while the other side received the same treatment protocol with a laser device switched off as a placebo (placebo side). All patients were instructed to receive skincare for both sides, such as debridement, antibiotic creams, and dressings with betadine solution. The diameter of DD lesion and the cutaneous blood flow of the knees and ankles sites were assessed before and after one month at the end of the intervention.Results: At the baseline, no significant differences existed between LLLT and placebo sides in the DD and skin blood flow at the knee and ankle sites (P > 0.05). Post-intervention, a significant improvement occurred in DD diameter and the skin blood flow of the knee and ankle sites in the LLLT side (P < 0.05), while the placebo side showed a significant improvement only in DD diameter (P < 0.05) and non-significant changes in skin blood flow (P > 0.05). Comparing both sides, all measures significantly favored LLLT.Conclusion: The findings of this study indicate that LLLT has beneficial effects on decreasing DD in T2D patients. Also, it was approved that the short term of LLLT is a safe modality to control DD in T2D patients

Avoiding routine postoperative voiding cystourethrogram: Predicting radiologic success for endoscopically treated vesicoureteral reflux

Introduction: Variability in the success rates for the endoscopic correction of vesicoureteral reflux (VUR) has prompted a debate regarding the use of routine postoperative voiding cystourethrogram (VCUG). This study examines the predictive performance of intraoperative mound morphology (IMM) and the presence of a postoperative ultrasound mound (PUM) on radiologic success, as well as investigates the role of using these two predictive factors as a composite tool to predict VUR resolution after endoscopic treatment. Methods: This retrospective study included children with primary VUR who underwent endoscopic correction with a double hydrodistension-implantation technique (HIT) and dextranomer/ hyaluronic acid copolymer. IMM was assessed intraoperatively. The presence of a PUM and VUR resolution were assessed by postoperative ultrasound (US) and VCUG, respectively. Radiologic success was defined as VUR resolution. Results: A total of 70 children (97 ureters) were included in the study. The overall radiologic success rate was 83.5%. There was no statistically significant association between radiologic success and IMM (85.2% with excellent and 87.5% with “other” morphology; p=0.81). The sensitivity and specificity of PUM for radiologic success in this study was 98% and 71%, respectively, while the sensitivity and specificity of the combined prediction model were 81.9% and 85.7%, respectively. Conclusions: We objectively demonstrated that IMM was a poor predictor of radiologic success and should be used with caution. In addition, the performance of a combined prediction model was inferior to the presence of a PUM alone. As such, selective use of postoperative VCUG may be guided solely by the presence of a PUM