Monitoring of Rehabilitation of Degraded Rangelands

The Algerian steppe covers an area of about 20 million ha, and is the barrier between the desert and the Mediterranean region. With more than 20 million sheep, overgrazing is an important issue resulting in continued degradation of the natural resources (Nedjraoui and Bedrani 2008). Trials of the rehabilitation of these ecosystems were undertaken in a participatory process with farmers complemented by some detailed monitoring of the responses in experimental plots (Hammouda 2009; Bouchareb 2012). This study reports on some results of the ecological monitoring and evaluation for a participatory project, in the steppe of South Algiers, conducted by a multidisciplinary team

Determinants of singleness among women aged 40 and over in Algeria: what relation to the labor market?

The decrease in the average age of marriage and the increase in loneliness among women in Algeria is a phenomenon that is becoming increasingly visible in society. In the coming years, the number of single people will increase. This article analyses the factors leading to increased loneliness among women aged 40 and over in Algeria based on data from the MICS6/2019 survey. The minimum age threshold was chosen because it corresponds to the age after which the probability of first marriage is almost zero based on Algerian statistics. The methodology of this study is stepwise Wald logistic regression. The paper built regression models based on two samples: the first (24,681 women aged 40 and over) and the second (4,329 women aged 50-54). For an empirical study of loneliness among women, it is proposed to analyze the following determinants: type of employment, type of social protection, place of residence, level of education, and age. Based on the results of the research, four main conclusions were formed. First, the odds of being single are 14.1 times and 4.23 times higher among job-seeking and working women, respectively, compared to non-working women. Due to the loss of hope to get married, women choose career development instead of building a family union. Under these conditions, women integrate into the labor market late. Since most of this category is unemployed and not of retirement age, they have low health insurance coverage. Based on this, to create decent living conditions for single women aged 40 and older, it is advisable to launch a program to improve the qualifications of these women, find ways to integrate them into the working environment and provide them with health insurance. Secondly, the long-term trend indicates that loneliness as a psychological phenomenon will increase every year in society, which will, accordingly, contribute to the strengthening of the imbalance in the marriage market. Late marriage and declining fertility are indicators of new patterns of behavior brought about by economic and social change. Thirdly, the level of well-being is also a statistically significant factor influencing the loneliness of women. Middle-class women are 1.27 times more likely to be single than upper-class women. Fourth, the survey revealed significant regional differences. Women in Algeria’s north-eastern and north-central regions are more likely to remain single. These results can be further explored through qualitative research

Validated Spectrofluorimetric Determination of Gemifloxacin in Pharmaceutical Preparations and Spiked Human Plasma

 A simple, sensitive and rapid spectrofluorimetric method was developed and validated for the determination of Gemifloxacin mesylate (GFX), in bulk powder, pharmaceutical preparations and biological fluids. The proposed method was based on complexation of GFX with AlCl3 as complexing agent then measuring the fluorescence of the resulted complex after enhancement with sodium dodecyl sulphate (SDS) in borate buffer (pH 8) at emission wavelength of 401 nm after excitation at 264 nm. Different experimental parameters affecting the fluorescence intensity were carefully studied and optimized to obtain the maximum fluorescence intensity. The developed method was validated according to International Conference on Harmonisation guidelines in terms of specificity, linearity, lower limit of quantification (LOQ) 0.54 ng.ml-1, lower limit of detection (LOD) 0.18 ng.ml-1, accuracy and precision. The proposed method was found to be rectilinear over the concentration range of 1-20 ng.ml-1with recovery percentage of 99.85±0.84. The proposed method was applied successfully for the determination of GFX in pharmaceutical preparations and spiked human plasma with recovery percentage of 99.97±0.79 and 99.96±1.73 respectively. The results were statistically analyzed and compared with a reference method and no significance difference was found between both methods

Dynamics of Diblock Copolymers in Dilute Solutions

We consider the dynamics of freely translating and rotating diblock (A-B), Gaussian copolymers, in dilute solutions. Using the multiple scattering technique, we have computed the diffusion and the friction coefficients D_AB and Zeta_AB, and the change Eta_AB in the viscosity of the solution as functions of x = N_A/N and t = l_B/l_A, where N_A, N are the number of segments of the A block and of the whole copolymer, respectively, and l_A, l_B are the Kuhn lengths of the A and B blocks. Specific regimes that maximize the efficiency of separation of copolymers with distinct "t" values, have been identified.Comment: 20 pages Revtex, 7 eps figures, needs epsf.tex and amssymb.sty, submitted to Macromolecule

Vulnérabilité climatique et stratégies productives d’adaptation des agropasteurs de Hadj Mechri

Abstract and keywords provided in EnglishInterannual variability which characterizes climate of northern Algeria is exacerbated with climate change. In the steppe, where agropastoral activities are totally dependent on rainfall, the increase of pluviometry variability aggravate agro-pastoralists vulnerability, particularly those weakly endowed and compromises their farming systems. Faced with this situation, these agropastoralists develop coping strategies. Those who remain on rangelands after droughts resort in rainy years to livestock guarding or to association in livestock /cereal crop that allow them to rebuild their capital by taking advantage of the occasional natural offer of rangelands.La variabilité interannuelle qui caractérise le climat de l’Algérie du Nord est exacerbée avec le changement climatique. Dans la steppe, où les activités agropastorales dépendent totalement de la pluviométrie, l’augmentation de la variabilité de cette dernière aggrave la vulnérabilité des agropasteurs, notamment ceux faiblement dotés et compromet leurs systèmes de production. Face à cette situation, ces agropasteurs développent diverses stratégies d’adaptation. Ceux qui se maintiennent sur les parcours après les périodes de sécheresse, recourent en bonnes années au gardiennage d’animaux ou à l’association d’élevage/céréaliculture qui leur permettent de reconstituer leur capital en tirant profit de l’offre naturelle occasionnelle des parcours

Chemical Investigation of Some Capparis Species Growing in Egypt and their Antioxidant Activity

Capparis cartilaginea and C. deserti growing in Egypt were investigated for their glucosiolates and rutin content. From Capparis cartilaginea four isothiocynates were isolated and identified using GC and EI/MS techniques. These compounds were butyl isothiocyanate (1), 6-methylsulphonylhexyl isothiocyanate (2), 7-methylsulphonylheptyl isothiocyanate (3) and 5-benzylsulphonyl-4-pentenyl isothiocyanate (4). In addition to compounds (1) and (2), two other compounds were isolated and identified from Capparis deserti. These compounds are 3-methylthiopropyl isothiocyanate (5) and [11-(2-butenylthio)6-undecenyl isothiocyanate] (6). Compounds (1), (2), (5) and (6) are reported in this study for the first time from Capparis deserti. The main flavonoid component in the studied species was isolated and identified as rutin by comparing the data with those reported. Also, quantitative evaluation of rutin in the two species was carried out by TLC-densitometric analysis. The antioxidant activity was done using diphenylpicrylhydrazyl (DPPH) radical scavenging method. The butanol fraction from C. cartilaginea and C. deserti showed the highest antioxidant properties

SANS polarization analysis with nuclear-spin-polarized He-3

A neutron spin filter based on transmission through nuclear-spin-polarized He-3 gas has been applied to polarization analysis of small angle neutron scattering (SANS). Such spin filters, which are based on the large spin dependence of the absorption of neutrons by He-3, make SANS polarization analysis possible because of their large angular acceptance. In the present experiment, a He-3-based analyzer was employed to separate nuclear scattering into its coherent and spin-incoherent components. Polarized He-3 analyzers were prepared by two different optical pumping methods and installed on the NG3 SANS instrument at the NIST Center for Neutron Research (NCNR). Measurements were taken on cellophane tape and silica gel, for which the scattering is almost completely incoherent and coherent, respectively, and on a combined sample. For the combined sample, separation of the coherent part from the incoherent part was successfully demonstrated using polarization analysis

An ABS control logic based on wheel force measurement

The paper presents an anti-lock braking system (ABS) control logic based on the measurement of the longitudinal forces at the hub bearings. The availability of force information allows to design a logic that does not rely on the estimation of the tyre-road friction coefficient, since it continuously tries to exploit the maximum longitudinal tyre force. The logic is designed by means of computer simulation and then tested on a specific hardware in the loop test bench: the experimental results confirm that measured wheel force can lead to a significant improvement of the ABS performances in terms of stopping distance also in the presence of road with variable friction coefficien

Modelling, control design, and analysis of the inner control's loops intended for single‐phase voltage‐controlled inverter‐based microgrid

In voltage-controlled voltage source inverters (VSIs)-based microgrids (MGs), the inner control is of prime interest task for guaranteeing safe and stable operation. In this paper, an in-depth investigation of the modelling, control design, and analysis of the voltage and current inner control loops intended for single-phase voltage-controlled VSIs is established. The main objective of this work is to provide a comprehensive study of the mathematical modelling, control design, and performance evaluation of the inner control's loops considering different proportional-integral (PI) controller types with and without compensation, and to determine the optimal scheme that can offer better performance in terms of implementation simplicity, robustness, and transient and steady-state responses. Thus, the mathematical closed-loop models of designed outer voltage and inner current control schemes based on PI, P, and feedforward controllers with and without compensation are, first, derived. Following this, a systematic and effective control design for tuning the different PI controllers’ parameters is proposed. Furthermore, an analysis revealing the performance of the designed voltage and current control schemes is provided. This analysis enables us to choose a P controller and PI feedforward controller for the current control loop and the voltage control loop, respectively. The chosen P and PI controllers should be simple; meanwhile, they should offer a wide bandwidth. A simulation study is carried out in MATLAB/Simulink software to assess the performance of the adopted inner control scheme for both linear and non-linear loads. In addition, an experimental setup, based on a TMS320F2837xD μC, of a single-phase VSI supplying linear and non-linear loads is built to verify the effectiveness and the robustness of the adopted inner controller. The results demonstrated: (1) the necessity of introducing the compensation term, which is responsible for offering control improvement against voltage perturbation, (2) the high tracking performance of the chosen controller in terms of dynamic and steady-state responses as well as its simplicity of implementation