Letter from Bernard M. Martin to Sonny Mead, 1967 March 22

Typewritten letter from Bernard M. Martin to Sonny Mead, dated March 22, 1967. Martin confirms Mead\u27s participation in the Fourth Annual Spring Arts Festival, and shares honorarium information.https://scholarscompass.vcu.edu/bang_docs/1052/thumbnail.jp

Renormalization factor and effective mass of the two-dimensional electron gas

We calculate the momentum distribution of the Fermi liquid phase of the homogeneous, two-dimensional electron gas. We show that, close to the Fermi surface, the momentum distribution of a finite system with $N$ electrons approaches its thermodynamic limit slowly, with leading order corrections scaling as $N^{-1/4}$. These corrections dominate the extrapolation of the renormalization factor, $Z$, and the single particle effective mass, $m^*$, to the infinite system size. We show how convergence can be improved analytically. In the range $1 \le r_s \le 10$, we get a lower renormalization factor $Z$ and a higher effective mass, $m^*>m$, compared to the perturbative RPA values.Comment: 4 pages, 3 figure

Pion-Nucleon Phase Shifts in Heavy Baryon Chiral Perturbation Theory

We calculate the phase shifts in the pion-nucleon scattering using the heavy baryon formalism. We consider phase shifts for the pion energy range of 140 to $200$ MeV. We employ two different methods for calculating the phase shifts - the first using the full third order calculation of the pion-nucleon scattering amplitude and the second by including the resonances $\Delta$ and $N^*$ as explicit degrees of freedom in the Lagrangian. We compare the results of the two methods with phase shifts extracted from fits to the pion-nucleon scattering data. We find good to fair agreement between the calculations and the phase shifts from scattering data.Comment: 14 pages, Latex, 6figures. Revised version to appear in Phys.Rev.

Penerapan Model Search-solve-create-share untuk Mengembangkan Kemampuan Penalaran Matematis Berbantuan Software Geogebra 4.4

Penelitian ini bertujuan untuk menelaah perbedaan kemampuan n penalaran matematis mahasiswa yang pembelajarannya menggunakan model SSCS tanpa bantuan geogebra, model SSCS dengan bantuan Software Geogebra 4.4 dan pembelajaran biasa. Metode yang digunakan dalam penelitian ini adalah metode kuasi eksperimen. Sampel yang diambil dalam penelitian ini adalah mahasiswa angkatan 2016 sebanyak tiga kelas pada mata kuliah Geometri Euclid. Dari ketiga kelas tersebut, satu kelas sebagai kelas eksperimen 1, satu kelas sebagai eksperimen 2 dan satu kelas lagi sebagai kelas kontrol. Hasil penelitian yang diperoleh yaitu terdapat perbedaan kemampuan penalaran matematis antara mahasiswa yang memperoleh model pembelajaran SSCS tanpa Geogebra, model SSCS berbantuan Geogebra dan model pembelajaran biasa. Kemampuan penalaran matematis tergolong cukup baik

ANALISIS KEMAMPUAN BERPIKIR KRITIS MATEMATIS SISWA SMP KELAS VII BERBANTUAN VISUAL BASIC APPLICATION FOR EXCEL PADA MATERI PECAHAN

The purpose of this research is to study the mathematical thinking skills of junior high school students in solving mathematical problems by using the Problem Based Learning approach on fractional materials. This study is a class action study conducted in class VII B Junior High School Pasundan Sidamulih. This study is a class action study. The subjects in the study were 22 students, 12 male students, and 10 female students. This study was conducted as many as 2 cycles, accompanied by the provision of pretes and postes.  The data collection technique carried out in this study uses test instruments in the form of pretes and postes, non-test instruments in the form of observation sheets of student and teacher activities. Based on the analysis obtained the average pretest score of 11.95 and the average postes score of 18.45. The data showed an increase in students' mathematical critical thinking skills by 21.74%

MENINGKATKAN KEMAMPUAN PEMECAHAN MASALAH MATEMATIS SISWA SMK PADA MATERI DETERMINAN MATRIKS MELALUI MODEL PROBLEM BASED LEARNING

This study aims to evaluate how students of class XI TKR 2 SMK Nurul Hidayah Pasundan develop their mathematical problem-solving skills using a problem-based learning technique on the topic of matrix determinants. This research is a classroom action research. The 2021–2022 school year's odd-numbered semester was employed for this study. There were 15 students of class XI TKR 2 who were used as research subjects. The following are the steps in this research: (1) Planning, (2) Action Implementation, (3) Observation and Evaluation, (4) Reflection. A learning outcome assessment used in this study measures students' ability to solve problems in relation to the determinants of the matrix., that is: (1) initial test, (2) first cycle test and second cycle test, (3) final test, and ( 4) observation sheets for researchers and students. The learning scenario had to be met by more than 80% of the activities performed in this study, and more than 80% of the individual students had to receive a score of at least 75. According to the study's findings, students in class XI TKR 2 at SMK Nurul Hidayah Pasundan can increase their capacity to solve mathematical problems by employing a problem-based learning approach when studying matrix determinants

Kinetic parameters for nutrient enhanced crude oil biodegradation in intertidal marine sediments

Availability of inorganic nutrients, particularly nitrogen and phosphorous, is often a primary control on crude oil hydrocarbon degradation in marine systems. Many studies have empirically determined optimum levels of inorganic N and P for stimulation of hydrocarbon degradation. Nevertheless, there is a paucity of information on fundamental kinetic parameters for nutrient enhanced crude oil biodegradation that can be used to model the fate of crude oil in bioremediation programmes that use inorganic nutrient addition to stimulate oil biodegradation. Here we report fundamental kinetic parameters (Ks and qmax) for nitrate-and phosphate-stimulated crude oil biodegradation under nutrient limited conditions and with respect to crude oil, under conditions where N and P are not limiting. In the marine sediments studied, crude oil degradation was limited by both N and P availability. In sediments treated with 12.5 mg/g of oil but with no addition of N and P, hydrocarbon degradation rates, assessed on the basis of CO2 production, were 1.10 ± 0.03 μmol CO2/g wet sediment/day which were comparable to rates of CO2 production in sediments to which no oil was added (1.05 ± 0.27 μmol CO2/g wet sediment/day). When inorganic nitrogen was added alone maximum rates of CO2 production measured were 4.25 ± 0.91 μmol CO2/g wet sediment/day. However, when the same levels of inorganic nitrogen were added in the presence of 0.5% P w/w of oil (1.6 μmol P/g wet sediment) maximum rates of measured CO2 production increased more than four-fold to 18.40 ± 1.04 μmol CO2/g wet sediment/day. Ks and qmax estimates for inorganic N (in the form of sodium nitrate) when P was not limiting were 1.99 ± 0.86 μmol/g wet sediment and 16.16 ± 1.28 μmol CO2/g wet sediment/day respectively. The corresponding values for P were 63 ± 95 nmol/g wet sediment and 12.05 ± 1.31 μmol CO2/g wet sediment/day. The qmax values with respect to N and P were not significantly different (P < 0.05). When N and P were not limiting Ks and qmax for crude oil were 4.52 ± 1.51 mg oil/g wet sediment and 16.89 ± 1.25 μmol CO2/g wet sediment/day. At concentrations of inorganic N above 45 μmol/g wet sediment inhibition of CO2 production from hydrocarbon degradation was evident. Analysis of bacterial 16S rRNA genes indicated that Alcanivorax spp. were selected in these marine sediments with increasing inorganic nutrient concentration, whereas Cycloclasticus spp. were more prevalent at lower inorganic nutrient concentrations. These data suggest that simple empirical estimates of the proportion of nutrients added relative to crude oil concentrations may not be sufficient to guarantee successful crude oil bioremediation in oxic beach sediments. The data we present also help define the maximum rates and hence timescales required for bioremediation of beach sediments

Two Photon Contribution to Polarization in K+→π+μ+μ−K^+ \rightarrow \pi^+ \mu^+ \mu^-

Short distance physics involving virtual top and charm quarks contributes to $\mu^+$ (and $\mu^-$) polarization in the decay $K^+ \rightarrow \pi^+ \mu^+ \mu^-$. Measurement of the parity violating asymmetry $(\Gamma_R - \Gamma_L)/(\Gamma_R + \Gamma_L)$, where $\Gamma_R$ and $\Gamma_L$ are the rates to produce right and left-handed $\mu^+$, may provide valuable information on the unitarity triangle. The parity violating asymmetry also gets a contribution from Feynman diagrams with two photon intermediate states. We estimate this two photon contribution to the asymmetry and discuss briefly the two photon contribution to time reversal odd asymmetries that involve both the $\mu^+$ and $\mu^-$ polarizations.Comment: (19 pages, 5 figures available on request. Uses phyzzx), CALT-68-1798, UCSD/PTH 92-2

Structure functions near the chiral limit

We compute hadron masses and the lowest moments of unpolarized and polarized nucleon structure functions down to pion masses of 300 MeV, in an effort to make unambiguous predictions at the physical light quark mass.Comment: 3 pages, 3 figures, Lattice2002(matrixel