Enhancing Magnetic Properties of Molecular Magnetic Materials: The Role of Single-Ion Anisotropy

Considerable efforts are being devoted to designing enhanced molecular magnetic materials, in particular single molecule magnets (SMMs) that can meet the requirements for future technologies such as quantum computing and spintronics. A current trend in the field is enhancing the global anisotropy in metal complexes using single-ion anisotropy. The work in this dissertation is devoted to the synthesis and characterization of new building blocks of the highly anisotropic early transition metal ion V(III) with the aim of incorporating them into heterometallic molecular materials. The results underscore the importance of tuning the local coordination environments of metal ions in order to ensure enhanced single ion anisotropy. A family of mononuclear axially distorted vanadium (III) compounds, A[L_(3)VX_(3)] (3-9) (X = F, Cl or Br, A^(+) = Et_(4)N^(+), nBu_(4)N^(+) or PPN^(+) , L_(3) = Tp or Tp* (Tp = tris(-1-pyrazolyl)borohydride), Tp* = tris(3,5-dimethyl-1-pyrazolyl)borohydride)), and [Tp*V(DMF)_(3)](PF_(6))_(2) were studied. Replacement of the Tp ligand in 3 with the stronger π-donor Tp* results in a near doubling of the magnitude of the axial zero-field splitting parameter D_(z) (D_(z) = -16.0 cm^(-1) in 3, and -30.0 cm^(-1) in 4) as determined by magnetic measurements. Such findings support the idea that controlling the axial crystal field distortion is an excellent way to enhance single-ion anisotropy. High Field-High Frequency EPR measurements on 4 revealed an even higher D value, -40.0 cm^(-1). Interestingly, compound 4 exhibits evidence for an out-of-phase ac signal under dc field. In another effort, a new series of vanadium cyanide building blocks, PPN[V(acac)_(2)(CN)_(2)]∙PPNCl (13) (acac = acetylacetonate), A[V(L)(CN)_(2)] (A^(+) = Et_(4)N^(+), L = N,N'-Ethylenebis(salicylimine) (14), A = PPN^(+), L = N,N'-Ethylenebis(salicylimine) (15), L = N,N'-Phenylenebis(salicylimine) (16), and L = N,N'-Ethylenebis(2-methoxysalicylimine) (17)) were synthesized. Magnetic studies revealed moderate Dz values (-10.0, 5.89, 3.7, 4.05 and 4.36 cm^(-1) for 13-17 respectively). The first family of cyanide-bridged lanthanide containing molecules with a trigonal bipyramidal (TBP) geometry, (Et_(4)N)_(2)[(Re(triphos)(CN)_(3))_(2)(Ln(NO_(3))_(3))_(3)]-∙4CH_(3)CN (19-27 with Ln = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy and Ho) were prepared using the [(triphos)Re(CN)_(3)]^(-) building block, results that add valuable information to our database of compounds with a TBP geometry. Magnetic studies revealed diverse magnetic responses including slow relaxation of the magnetization at zero field for 25 and 26 , an indication of SMM behavior

A Novel Design and Implementation of FBMC Transceiver for Low Power Applications

The complex structure of the Filter Bank Multicarrier (FBMC) communication system is the main drawback affecting the performance of the system and causes a high-power consumption. The complexity arises from using a polyphase filter bank, which consists of fast Fourier Transform/ Inverse Fast Fourier Transform (FFT/IFFT) processors and a filter bank of Finite Impulse Response (FIR) filters. This paper presents the analysis and the implementation of a new design model for FBMC transceiver in which the polyphase filter is removed completely in both transmitter and receiver and uses instead of it, a multi-level cascaded structure of FIR subfilters. The coefficients of each subfilter selected using an optimization algorithm to minimize the amplitude of sidelobes compared to the amplitude of the main lobe in the frequency response of the subfilter. The proposed design reduces the number of multiplications compared to the conventional design by 65%. The field-programmable gate array (FPGA) implementation results indicate that the proposed architecture saves 24% of resources of the FPGA board, works faster, and saves 27% of power consumption compared to conventional FBMC transceiver

FIRST YEAR SEMINAR FOSTERING 21ST CENTURY SKILLS: A STUDY OF QATAR UNIVERSITY FRESHMEN PERSPECTIVES

The overarching purpose of the present study was to investigate the perspectives of first-year students who are enrolled in First-Year Seminar (UNIV 100) course offered at Qatar University, with regard to the successfulness of the course in fostering 21st century skills; namely, study skills, critical thinking, problem solving, personal growth, collaboration, communication, digital information literacy, and civic engagement skills. A quantitative method design was utilized. A questionnaire including close-ended items was developed and administered online to all first-year students enrolled in the course during Fall 2018 semester. The close-ended questions comprised Likert-scale and rating scale multiple-choice items. A number of 307 first-year students voluntarily completed the questionnaire. SPSS V. 25 was used to run data analysis. Frequencies, percentages, means, standard deviation, Welch's test and ANOVA were used to analyze the data. The findings yielded that the majority of participants agreed that the course was successful in fostering the set of the 21st century skills being investigated. Results show statistical significant differences attributed to the variable of gender; in particular, differences among means of gender groups were significant for study skills, personal growth, collaboration and communication, digital information literacy, and social responsibility. However, no statistically significant differences among gender groups were reported in problem solving skills. It was noticed that the differences among means of students’ groups based on their nationality or college were not significant for all the skills. The study also revealed that the majority of first-year students perceived that the course was useful to them. Overall, the findings of this study suggest that the course was successful in fostering the 21st century skills. Implications and recommendations for further practice and future research are presented

Effect of Royal Jelly on the Fertilizing Ability of Buffalo Spermatozoa In Vitro

The aim of the present study was to assess the effect of addition of Royal jelly in presence of heparin on buffalo (Bubalus Bubalis) sperm motility, acrosome reaction and in vitro fertilization (IVF) of buffalo oocytes. Frozen buffalo spermatozoa from five bulls were thawed and motile fraction was obtained by swim up technique. The spermatozoa were washed, treated with100 µg/ml heparin, and then exposed to 0.4% Royal Jelly (RJ) for 3 h. Sperm motility, acrosomal integrity and fertilization rate of matured oocytes were assessed at 1, 2 and 3 h. The percentages of sperm motility, intact acrosome and fertilization rate of matured oocytes were higher (P<0.05) in 0.4% RJ compared to that in the control. After 2 h of incubation the percentage of motility, intact acrosome of spermatozoa and fertilization rate of matured oocytes, respectively, were 93.6 %, 77.6% and 72.6% in 0.4% RJ. These results suggest that treating buffalo sperm with 0.4% RJ in combination with heparin is effective not only to induce sperm acrosome reaction but also is effective for in vitro fertilizing capacity of the cryopreserved buffalo spermatozoa

Preface

Journal of Buffalo Science, Volume 1 Number 1, Prefac

In Vito Fertilization in Buffaloes: A Review

This is the review of original data concerning the effect of some factors on oocyte development in vitro of buffaloes. In vitro fertilization is a multi - step process: oocytes maturation, fertilization and embryo culture. In vitro fertilization is strongly influenced by events occurring during oocyte maturation, fertilization and the subsequent development of the fertilized oocytes. With the advancement of IVF procedures, variability in developmental rate and viability of in vitro produced buffalo embryos so, improving the efficiency and identifying the sources of variations between IVF systems are more important when routinely producing blastocysts from individuals of high genetic merits. Also, the development of specific culture regimes capable of supporting in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC) to the blastocyst stage is highly desirable in breeding systems. This paper discusses the technical aspects of the procedures involved in in vitro fertilization of buffaloes

Relative abundance and diversity of waterbirds in a Rhizophora mangrove forest in Iran.

This study determined the abundance and diversity of waterbirds at Gaz and Hara River Deltas (GHRD) mangroves, southern of Iran. Point count sampling method that included 35 points along three transects was employed in this study. A total of 16687 waterbird observations, belonging to 38 waders, 15 seabirds and only one waterfowl species were recorded at GHRD international wetland. The observations were categorized based on different season, where a total of 4813 (37 spp.), 9445 (48 spp.), 1759 (30 spp.) and 670 (15 spp.) observations were recorded in the fall, winter, spring and summer, respectively. The Eurasian Curlew (3689 observations, 22.11%), Great Cormorant (1309 observations, 7.84%) and Terek Sandpiper (1065 observations, 6.38%) dominated the area. The Scolopacidae (7500 observations, 44.95%) and Laridae (2631 observations, 15.77%) were the most abundant family and Dromatidae (6 observations, 0.04%), Podicepedidae (4 observations, 0.02%) and Recurvirostridae (2 observations, 0.01%) were among families with the lowest number. The mean number of observations of waders during fall, winter, spring and summer were 104.11±36.60, 222.32±67.74, 22.62±6.82, and 10.16±3.91respectively, while of seabirds were 56.53±25.05, 71±28.15, 54.24±21.15 and 17.29±9.52, respectively. The similarity between seasons of fall and winter were highest (72 %). Abundance of waterbirds was positively correlated with density of molluscs and mudskipper, R. mucronata height and stand basal area as well as percentage of clay in soil (R2= 0.99, p < 0.01). In addition, species of Oriental White-eye Warbler (Zosterops palpebrozus) is a new record for GHRD. The great importance of GHRD for migrant waders and seabirds, and also for landbirds, must be recognized and the protection of this site from threats must be thoroughly enhanced

ASSESSMENT THE YIELD AND QUALITY OF NIGELLA SATIVA UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

Objective: Nowadays, one of the growing industries is the herbal drug-based medicaments. This study sought to assess the quality and yield characterizes of black cumin under different locations through Egypt to introduce final analysis information for producers and exporters in Egypt. Methods: This experiment was carried out in seven sites in different locations through Egypt to assess the growth, yield and essential oil content of black cumin plants as following; four sites in El-Minya Governorate, two sites in Bahariya Oasis, and one site in Aswan Governorate. Results: Cultivation locations significantly affected on quality and growth characteristics. The highest seed and fixed oil yields (830 kilogram seeds and 206 kilogram fixed oil) were observed under clay loam soil (Old Land farm), while the lowest yields (500 kilogram seeds and 105 kilogram fixed oil) were observed under sandy soil (El-Nanaaih farm) at El-Menya. The highest content of active substance (Fixed oil %) was observed in clay loam sandy soil of Sekem farm and the lowest in Lena farm with sandy soil at Bahariya Oasis. Neither seed yield nor fixed oil content showed significant correlation with Na+, Cl-, and HCO3--of irrigation water. Although plants cultivated in Wadi El-Nokra at Aswan produced low fixed oil content (18.3%), main components, Linoleic and Oleic acid, were relatively high. Conclusion: The assessment of Nigella sativa under different locations gave evidence of the interactions between weather and soil properties and their impact on the quality and yield of oil of Nigella sativa plants