Proportional-integral-plus control applications of state-dependent parameter models

This paper considers proportional-integral-plus (PIP) control of non-linear systems defined by state-dependent parameter models, with particular emphasis on three practical demonstrators: a microclimate test chamber, a 1/5th-scale laboratory representation of an intelligent excavator, and a full-scale (commercial) vibrolance system used for ground improvement on a construction site. In each case, the system is represented using a quasi-linear state-dependent parameter (SDP) model structure, in which the parameters are functionally dependent on other variables in the system. The approach yields novel SDP-PIP control algorithms with improved performance and robustness in comparison with conventional linear PIP control. In particular, the new approach better handles the large disturbances and other non-linearities typical in the application areas considered

Total and Available Copper and Zinc in Soils Affected by Palm Oil Mill Effluent in Oghareki, Oghara Kingdom, Delta State, Nigeria

This study evaluates the physicochemical characteristics, total and available copper and zinc in soils affected by four palm oil mills effluent (POME) of Oghareki in Oghara Kingdom, Delta State, Nigeria using standard methods. The results showed generally increased pH, organic matter, electrical conductivity, available phosphorus, exchangeable bases and cation exchange capacity (CEC), compared to the non-POME-contaminated soils. Concentrations of the exchangeable bases increased in the order, Na < Mg < K <Ca, in both the POME- and non-POME-soils. Data of total copper and zinc also revealed higher amounts in the POME soils. Total copper in POME- and non-POME-soils gave means of 0.232 and 0.212 mmol/kg, and 0.237 and 0.219 mmol/kg in respect of zinc, respectively, with no significant difference (P<0.05). The increased amounts of the different soil physicochemical parameters recorded in the POME-affected soils may be accounted for by their enhancement with every discharge of the effluent on one hand, and perhaps, the greater level of biodegradation and mineralization of the constituent organic matter, on the other. The study lends support to the view that raw palm oil mill effluent (POME) could alter the physicochemical properties of the receiving environment

Unprecedented chemical transformation: crystallographic evidence for 1,1,2,2-tetrahydroxyethane captured within an Fe6Dy3 single molecule magnet

A nonanuclear {Fe6Dy3} coordination cluster displaying SMM behaviour in which an unprecedented chemical transformation provides structural information for the existence of 1,1,2,2-tetrahydroxyethane is reported

Economic evaluation of prevention of mother – to – child – transmission of HIV/AIDS interventions in developing countries : a systematic review

Les gouvernements mondiaux et les organismes internationaux ont placé une haute priorité dans la prévention de la transmission mère-enfant du VIH. Cependant, bien qu'il y ait eu des progrès énormes rapportés dans des nations industrialisées, la situation dans les pays en voie de développement est encore déplorable; on y constate un grand écart entre l’engagement international pour réduire cette voie de transmission et l'accès aux interventions. Ceci peut être attribué à la situation économique déplorable dans plusieurs pays en voie de développement. Des interventions prioritaires en santé doivent donc être soigneusement sélectionnées afin de maximiser l'utilisation efficace des ressources limitées. L’évaluation économique est un outil efficace qui peut aider des décideurs à identifier quelles stratégies choisir. L'objectif de cette revue systématique est de recenser toutes les études d'évaluation économique existantes qui ont été effectuées dans les pays en voie de développement sur la prévention de la transmission mère-enfant du VIH. Notre revue a retenu 16 articles qui ont répondu aux critères d'inclusion. Nous avons conçu un formulaire pour l’extraction de données, puis nous avons soumis les articles à un contrôle rigoureux de qualité. Nos résultats ont exposé un certain nombre de défauts dans la qualité des études choisies. Nous avons également noté une forte hétérogénéité dans les estimations des paramètres de coût et d'efficacité de base, dans la méthodologie appliquée, ainsi que dans les écarts utilisés dans les analyses de sensibilité. Quelques interventions comportant la thérapie à la zidovudine ou à la nevirapine à court terme se sont avérées rentables, et ont enregistré des valeurs acceptables de coût-utilité. Les résultats des évaluations économiques analysées dans cette revue ont varié sur la base des facteurs suivants : la prévalence du VIH, la classification du pays selon le revenu, les infrastructures disponible, les coûts du personnel, et finalement les coûts des interventions, particulièrement les prix des médicaments.Local governments worldwide and international organizations have placed a high priority in the Prevention of Mother – To – Child – Transmission (pMTCT) of HIV. However, though there have been reports of tremendous progress in achieving these goals in industrialised nations, the situation in developing countries is still deplorable. In developing countries, there is a significant gap between the global and local policy commitments to reduce Mother – To – Child – Transmission (MTCT) of HIV and the access to pMTCT interventions. This can be attributed to the dire economic situation within developing countries. Healthcare interventions therefore need to be strategically prioritized in order to make maximum efficient use of these scarce resources. An effective tool to assist decision makers in identifying which strategies represent value for money is economic evaluation of these interventions. The objective of this study is systematically pool all the existing economic evaluation studies that have been carried out in developing countries on the pMTCT of HIV/AIDS, in order to present the best fit, affordable, yet effective intervention (s). Our review retained 15 articles that met the inclusion criteria. We designed an extraction form which we used to collect relevant data, after which we subjected the articles to a rigorous quality checklist. Our results exposed a number of flaws in methodological quality of the selected studies. We also recorded widespread heterogeneity in the assumptions used to estimate base case cost and effectiveness parameters, in the methodology applied, as well as in the range of valued used in sensitivity analyses. Some interventions involving short course zidovudine or nevirapine therapy were found to be cost effective, and recorded acceptable cost-utility values. The results of economic evaluations analyzed in this review varied based on the following factors: HIV prevalence, country income classification, available infrastructure, staff costs, and ultimately costs of the interventions, especially drug prices

Polymorphism of the testis-specific serine/threonine kinase 2 gene and risk of asthenozoospermia in Côte d'Ivoire

Background: The testis-specific serine/threonine protein kinase (TSSK2) is an indispensable protein responsible for the mobility of spermatozoa expressed specifically in the germ cells during spermatogenesis and present in the mature spermatozoa. Its gene mutation could constitute a risk of infertility. The aim of this study is to investigate the polymorphism of this TSSK2 gene in men with asthenozoospermia.Methods: The ejaculates were obtained from patients attending the reproductive biology unit of Institut Pasteur of Côte d’Ivoire for their spermiological evaluations. The semen analyses are performed with the automatic sperm analyzer SQA-Vision. 30 sperms, including 20 asthenozoosperms and 10 normosperms, were selected from their spermiological results and the spermatozoa DNA was extracted by the phenol/chloroform method. Direct Sequencing of the spermatozoa DNA fragments was done using the Sanger method. The frequencies of mutation were analysis with the Fisher and Mann-Whitney tests.   Results: It was revealed 17 mutations in 22 ejaculates. The frequent mutations are c.839C>T (T280M), c.816G>C (L372L), c.1026G>A (R342R), c.785A>C (H262P) and c.80A>G (K27R) with respectively frequencies of 50.0%, 26.67%, 16.67%, 13.33% and 10.0%. The analysis of these mutations indicated a significant difference in the frequency of occurrence of mutations between normosperms and asthenozoosperms (p-value = 0.01).Conclusions: This study shows that mutations in the TSSK2 gene are more common in asthenozoosperm ejaculates than normosperm ejaculates. This fact suggests the probable association of mutations in the TSSK2 gene with asthenozoospermia

Diagnostic Étiologique Échographique des Douleurs Pelviennes Aigues de la Femme en Côte d’Ivoire

Introduction : les douleurs pelviennes aigues chez la femme sont fréquentes et objet d’exploration échographique systématique dans notre pratique quotidienne. Objectif : contribuer à la recherche étiologique des douleurs pelviennes aigues (DPA) de la femme dans une zone où l’outil échographique est pratiquement le seul moyen d’imagerie accessible. Patiente et méthodes : étude prospective d’une durée de 6 mois réalisée au centre hospitalo-universitaire de Yopougon (Abidjan-Côte d’Ivoire). Une série continue de 153 femmes chez qui nous avons réalisé une échographie pelvienne au motif de DPA ont été enrôlées. Les examens échographiques ont été réalisées à l’aide de 3 sondes (convexe, linéaire et endocavitaire) en mode B et Doppler. Résultats : l’âge moyen des patientes était de 30, 2 ans avec des extrêmes de 12 et 68 ans. Les échographies étaient normales dans 25,5% et objectivaient une pathologie dans 74,5 % des cas. Ces pathologies concernaient les organes génitaux internes dans 89,5% des cas et dans 10,5% des cas il s’agissait de pathologie extra-génitale. Les ovaires étaient les organes génitaux les plus concernés (64,1%) suivis de l’utérus (28,2%) et des trompes (7,7%). Les causes extra-génitales étaient la hernie inguinale (4 cas), l’appendicite aigüe (5 cas), la sigmoïdite (1 cas) et la lithiase du bas uretère (2 cas). Conclusion : une proportion non négligeable de causes extra-génitales des douleurs pelviennes, objectivée dans notre étude, impose un examen clinique minutieux de toute la sphère hypogastrique voire abdominale par les cliniciens. L’utilisation de la sonde linéaire de haute fréquence qui n’est pas toujours sollicitée par les échographistes, au cours de la prise en charge des DPA devrait être préconisée. Introduction: Acute pelvic pain in women is common and systematically explored by ultrasound in our daily practice. Objective: Contribute to the aetiological research of women's acute pelvic pain (APD) in an area where the ultrasound tool is practically the only means of accessible imagery. Patient and methods: A prospective study lasting 6 months was carrried out at the Yopougon University Hospital Center (Abidjan-Ivory Coast). A continuous series of 153 women who had a pelvic ultrasound for DPA were enrolled. Ultrasound examinations were performed using 3 probes (convex, linear and endocavitary) in B and Doppler mode. Results: The mean age of the patients was 30, 2 years with extremes of 12 and 68 years. About a quarter (25.5%) of the ultrasound examinations were normal and in 74.5% of cases, a pathology was objectified. These pathologies concerned the internal genital organs in 89.5% of the cases and in 10.5% of cases they were extragenital pathologies. The ovaries were the most affected genitals (64.1%)followed by the uterus (28.2%) and the fallopian tubes (7.7%). Extra-genital causes were inguinal hernia (4 cases), acute appendicitis (5 cases), sigmoiditis (1 case) and lithiasis of the lower ureter (2 cases). Conclusion: a significant proportion of extragenital causes of pelvic pain, objectified in our study, requires a careful clinical examination of the whole hypogastric or even all abdominal regions by clinicians and the use of the high frequency linear probe which is not not always solicited by sonographers, during the care of the DPA

A New Model for Predicting Liquid Loading in Multiphase Gas Wells

Liquid loading problem occurs when there is accumulation of liquid in the wellbore. The ultimate desire of this phenomenon is to reduce gas recovery or completely kill the production well. This challenge can lead to loss in well deliverability and as a result recovery of gas becomes low and cause heavy damage that the remedy would be costly. So many scholars have modeled to predict liquid loading onset but over the years the results gotten have shown one discrepancies or the other and could be difficult to use because of the challenges facing in predicting the bottomhole pressure of a multiphase flow. Numerical integration method was used in this new model while considering the introduction of valve equation along the functional nodes to the fundamental equation. The pressure drop across the functional node has not been considered by previous scholars. The result is very effective when compared analytically with other established work. The results also show the onset of transient flow and how quickly it stabilizes. Furthermore, the numbers of correctly predicted wells when validated with data was higher than the previous result

Assisted Self-Assembly to Target Heterometallic Mn-Nd and Mn-Sm SMMs: Synthesis and Magnetic Characterisation of [Mn7_{7}Ln3_{3}(O)4_{4}(OH)4_{4}(mdea)3_{3}(piv)9_{9}(NO3_{3})3_{3}] (Ln=Nd, Sm, Eu, Gd)**

Assisted self-assembly by using a preformed [Mn$_{6}$O$_{2}$(piv)$_{10}$(4-Me-py)$_{2}$(pivH)$_{2}$] (1) (pivH=pivalic acid) cluster leads to 3 different outcomes of the reaction with Ln(NO$_{3}$)$_{3}$ ⋅ xH$_{2}$O (Ln=Pr−Ho and Y): Mn$_{7}$Ln$_{3}$ and in some cases the inverse butterfly Mn$_{2}$Ln$_{2}$ for Ln=Pr−Eu, Mn$_{5}$Ln$_{4}$ for Ln=Tb-Ho and in the special case of Gd all three possibilities can form. Whilst the magnetic properties for the Mn$_{5}$Ln$_{4}$ systems show the expected known SMM properties, for Mn$_{7}$Ln$_{3}$ two new examples of Nd- and Sm-containing SMMs have been discovered. in an assisted self-assembly approach starting from the [Mn$_{6}$O$_{2}$(piv)$_{10}$(4-Me-py)$_{2}$(pivH)$_{2}$] cluster a family of Mn−Ln compounds (Ln=Pr−Yb) was synthesised. The reaction of [Mn$_{6}$O$_{2}$(piv)$_{10}$(4-Me-py)$_{2}$(pivH)$_{2}$] (1) with N-methyldiethanolamine (mdeaH$_{2}$) and Ln(NO$_{3}$)$_{3}$ ⋅ 6H$_{2}$O in MeCN generally yields two main structure types: for Ln=Tb−Yb a previously reported Mn$_{5}$Ln$_{4}$ motif is obtained, whereas for Ln=Pr−Eu a series of Mn$_{7}$Ln$_{3}$ clusters is obtained. Within this series the Gd$^{III}$ analogue represents a special case because it shows both structural types as well as a third Mn$_{2}$Ln$_{2}$ inverse butterfly motif. Variation in reaction conditions allows access to different structure types across the whole series. This prompts further studies into the reaction mechanism of this cluster assisted self-assembly approach. For the Mn$_{7}$Ln$_{3}$ analogues reported here variable-temperature magnetic susceptibility measurements suggest that antiferromagnetic interactions between the spin carriers are dominant. Compounds incorporating Ln=Nd$^{III}$(2), Sm$^{III}$(3) and Gd$^{III}$ (5) display SMM behaviour. The slow relaxation of the magnetisation for these compounds was confirmed by ac measurements above 1.8 K

Threefold enhancement of superconductivity and the role of field-induced odd-frequency pairing in epitaxial aluminum films near the 2D limit

BCS theory has been widely successful at describing elemental bulk superconductors. Yet, as the length scales of such superconductors approach the atomic limit, dimensionality as well as the environment of the superconductor can lead to drastically different and unpredictable superconducting behavior. Here, we report a threefold enhancement of the superconducting critical temperature and gap size in ultrathin epitaxial Al films on Si(111), when approaching the 2D limit, based on high-resolution scanning tunneling microscopy/spectroscopy (STM/STS) measurements. In magnetic field, the Al films show type II behavior and the Meservey-Tedrow-Fulde (MTF) effect for in-plane magnetic fields. Using spatially resolved spectroscopy, we characterize the vortex structure in the MTF regime and find strong deviations from the typical Abrikosov vortex. We corroborate these findings with calculations that unveil the role of odd-frequency pairing and a paramagnetic Meissner effect. These results illustrate two striking influences of reduced dimensionality on a BCS superconductor and present a new platform to study BCS superconductivity in large magnetic fields

Tetranuclear Zn/4f coordination clusters as highly efficient catalysts for Friedel-Crafts alkylation

A series of custom-designed, high yield, isoskeletal tetranuclear Zn/4f coordination clusters showing high efficiency as catalysts with low catalytic loadings in Friedel-Crafts alkylation are described for the first time. The possibility of altering the 4f centers in these catalysts without altering the core topology allows us to further confirm their stability via EPR and NMR, as well to gain insights into the plausible reaction mechanism, showcasing the usefulness of these bimetallic systems as catalysts