The Effect of Summer Enrollment in The Boys and Girls Club on Adolescent Peer Attachment

The formation of friendships is an important developmental step for adolescents. Peer attachment is an attachment relationship that adolescents develop with their closest friends. Research studying peer attachment has divided it into three major categories: trust, communication, and alienation, the later of which is an inverse measure of peer attachment. Youth organizations like the Boys and Girls Club of America (BGCA) offers places outside of school where adolescents can socialize with their peers. This study measured whether the BGCA had a significant impact on increasing peer attachment, trust, and communication while reducing alienation. Adolescents were tested at a local BGCA using the peer portion of the Inventory of Parent and Peer Attachment. Adolescents were tested again after attending the BGCA for a summer period. One-way t tests were used to calculate the change in IPP A scores. There was no significant change in scores on total peer attachment; t (7) = .129, ns or on any of the three subscales, communication; t (7) = .842, ns, alienation; t (7) = 1.383, ns, and trust; t (7) = .437, ns. A Pearson correlation revealed a two-month test-retest reliability of .844. This is very consistent with the original test-retest reliability provided in the norming sample. Several factors may have influenced the lack of significant results: the small sample size, untrustworthy responses, the young age of the sample, and the possibility that peer attachment is a relatively stable trait

Comparative OBSI Testing in Northern California: The Davis Rodeo

The report describes a series of comparative on-board sound intensity (OBSI) tests performed on 19 different pavement sections by three different teams and vehicles using five different tires to determine variations among them for noise testing. The testing considered the tires’ rubber durometer hardness, tread depth, and accumulated mileage, and measured sound levels using the on-board sound intensity method. The results of these measurements are compared with similar testing performed earlier, and showed that the average differences measured by the teams were smaller and the maximum OBSI ranges were larger than those made in earlier testing

High Field de Haas - van Alphen Studies of the Fermi Surfaces of LaMIn5_{5} (M = Co, Rh, Ir)

We report measurements of the de Haas - van Alphen effect on a series of compounds, LaMIn$_{5}$ (M = Co, Rh, Ir). The results show that each of the Co and Ir Fermi surfaces (FSs) exhibit some portions that are two dimensional and some portions that are three dimensional. The most two dimensional character is exhibited in LaCoIn$_{5}$, less two dimensional behavior is seen in LaIrIn$_{5}$, no part of Fermi surface of LaRhIn$_{5}$ is found to have a two dimensional character. Thus the two dimensionality of portions of the FSs is largely determined by the d character of the energy bands while all of the effective masses remain $\leq$ 1.2. This fact has implications for the causes of the heavy fermion nature of superconductivity and magnetism in the Ce-based compounds having the similar composition and structure. All of the measurements were performed at the National High Magnetic Field Laboratory using either cantilever magnetometry or field modulation methods.Comment: 10 pages, 4 figure

Magnetization Measurements on Single Crystals of Superconducting Ba0.6K0.4BiO3

Extensive measurements of the magnetization of superconducting single crystal samples of Ba0.6K0.4BiO3} have been made using SQUID and cantilever force magnetometry at temperatures ranging between 1.3 and 350 K and in magnetic fields from near zero to 27 T. Hysteresis curves of magnetization versus field allow a determination of the thermodynamic critical field, the reversibility field, and the upper critical field as a function of temperature. The lower critical field is measured seperately and the Ginzburg-Landau parameter is found to be temperature dependent. All critical fields have higher T = 0 limits than have been previously noted and none of the temperature dependence of the critical fields follow the expected power laws leading to possible alternate interpretation of the thermodynamic nature of the superconducting transition.Comment: 33 pages, 11 figures, accepted for publication in Philosophical Magazine B on 7 August 1999. This paper supplies the experimental details for the argument presented in our PRL 82 (1999) p. 4532-4535 (also at cond-mat/9904288

Aplikasi Steganography untuk Enkripsi Image To Image dengan Metode Spread Spectrum

Steganography  adalah  suatu  seni  dan  ilmu  (science)  dalam  menyembunyikan  keberadaan  pesan menggunakan  metode  tertentu  sehingga  hanya  penerima  saja  yang  mengetahui  keberadaan  pesan  tersebut. Dalam steganography, ada beberapa media digital yang dapat digunakan sebagai cover untuk menyembunyikan keberadaan sebuah pesan, seperti : citra, audio, teks, video. Dalam tugas akhir ini, media cover yang digunakan adalah citra digital dengan format piksel 24-bit Metode Steganografi yang dimaksud adalah metode yang menempatkan informasi di dalam derau semu di keseluruhan cover image. Untuk mencapai tujuan yang diinginkan tersebut, maka akan dibutuhkan komponen tambahan, yaitu spread spectrum yang akan mentransmisikan sebuah sinyal pita informasi yang sempit ke dalam sebuah kanal pita lebar dengan penyebaran frekuensi. Hasil analisis menunjukkan  bahwa  implementasi  ini  dapat  menjalankan  kedua  tugas  utama dalam sistem steganography (penyisipan  dan  pengekstrakan)  dengan  baik.  Dan  dari  hasil  percobaan yang dilakukan terhadap beberapa citra uji, dapat diketahui bahwa citra yang baik untuk digunakan sebagai citra cover adalah citra yang memiliki kekontrasan yang tinggi

The Fermi surface of CeCoIn5: dHvA

Measurements of the de Haas - van Alphen effect in the normal state of the heavy Fermion superconductor CeCoIn5 have been carried out using a torque cantilever at temperatures ranging from 20 to 500 mK and in fields up to 18 tesla. Angular dependent measurements of the extremal Fermi surface areas reveal a more extreme two dimensional sheet than is found in either CeRhIn5 or CeIrIn5. The effective masses of the measured frequencies range from 9 to 20 m*/m0.Comment: 4 pages, 2 figures, submitted to PRB Rapid

Anomalous Superconducting Properties and Field Induced Magnetism in CeCoIn5

In the heavy fermion superconductor CeCoIn5 (Tc=2.3K) the critical field is large, anisotropic and displays hysteresis. The magnitude of the critical-field anisotropy in the a-c plane can be as large as 70 kOe and depends on orientation. Critical field measurements in the (110) plane suggest 2D superconductivity, whereas conventional effective mass anisotropy is observed in the (100) plane. Two distinct field-induced magnetic phases are observed: Ha appears deep in the superconducting phase, while Hb intersects Hc2 at T=1.4 K and extends well above Tc. These observations suggest the possible realization of a direct transition from ferromagnetism to Fulde-Ferrel-Larkin-Ovchinnikov superconductivity in CeCoIn5.Comment: 4 pages, 3 figure

Space construction system analysis. Part 2: Platform definition

The top level system requirements are summarized and the accompanying conceptual design for an engineering and technology verification platform (ETVP) system is presented. An encompassing statement of the system objectives which drive the system requirements is presented and the major mission and subsystem requirements are described with emphasis on the advanced communications technology mission payload. The platform design is defined and used as a reference configuration for an end to space construction analyses. The preferred construction methods and processes, the important interactions between the platform design and the construction system design and operation, and the technology development efforts required to support the design and space construction of the ETVP are outlined