Correlation functions of the One-Dimensional Random Field Ising Model at Zero Temperature

We consider the one-dimensional random field Ising model, where the spin-spin coupling, $J$, is ferromagnetic and the external field is chosen to be $+h$ with probability $p$ and $-h$ with probability $1-p$. At zero temperature, we calculate an exact expression for the correlation length of the quenched average of the correlation function $\langle s_0 s_n \rangle - \langle s_0 \rangle \langle s_n \rangle$ in the case that $2J/h$ is not an integer. The result is a discontinuous function of $2J/h$. When $p = {1 \over 2}$, we also place a bound on the correlation length of the quenched average of the correlation function $\langle s_0 s_n \rangle$.Comment: 12 pages (Plain TeX with one PostScript figure appended at end), MIT CTP #220

Diagnosis and endovascular treatment of an internal mammary artery injury

Internal mammary artery (IMA) disruption after blunt chest trauma is rare. In some instances, it may occur after mild chest trauma with minor external physical findings. However, prompt diagnosis and treatment are necessary, as it can be associated with vascular and parenchymal injuries. We report a case of blunt chest trauma resulting in a sternal fracture associated with an IMA injury, active anterior mediastinal bleeding, bilateral lung contusions, and a left hemothorax. It was successfully treated by selective embolization to the left IMA branch and chest tube placement

Active case-finding for TB among incarcerated women in Peru

Carta al editorRevisión por pare

Transporting Isowean Pigs—Part II: Responses to Potential In-transit Thermal Conditions

The goal of this research was to explore the feasibility and protocols to transport isowean pigs long distance. This study was the second part of the effort that examined the thermal environment aspects of such a practice. Isowean pigs of PIC genetics (10 to 12 days old) were subjected to simulated 54-h in-transit temperature pattern of 80 ± 0, 5, 10 or 15°F. The pigs were provided with water supplement (average dosage of 2 lb/pig) during the treatment period and ad libitum feeding during a 14-d growth period. All pigs had similar weight loss (8.4 to 8.9% of their initial body weight) during the treatment period. The only difference in total weight gain during the growth period was between pigs previously exposed to 80 ± 15°F (8.33 lb) and those previously exposed to 80 ± 10°F (9.15 lb) (P0.05). All pigs showed similar physiological and energetic responses during both treatment and growth periods. The treatment period led to elevated concentrations of hematocrit, plasma protein, blood urea nitrogen, sodium and chloride, but declined glucose level (

Removal of antiretroviral drugs stavudine and zidovudine in water under UV254 and UV254/H2O2 processes: Quantum yields, kinetics and ecotoxicology assessment

The concentration of antiretroviral drugs in wastewater treatment plants (WWTP) effluents and surface waters of many countries has increased significantly due to their widespread use for HIV treatment. In this study, the removal of stavudine and zidovudine under UV254 photolysis or UV254/H2O2 was investigated in a microcapillary film (MCF) photoreactor, using minimal water samples quantities. The UV254 quantum yield of zidovudine, (2.357 ± 0.0589)·10−2 mol ein−1 (pH 4.0–8.0), was 28-fold higher that the yield of stavudine (8.34 ± 0.334)·10−4 mol ein−1 (pH 6.0–8.0). The second-order rate constant kOH,iof reaction of hydroxyl radical with the antiretrovirals (UV254/H2O2 process) were determined by kinetics modeling: (9.98 ± 0.68)·108 M−1 s−1 (pH 4.0–8.0) for zidovudine and (2.03 ± 0.18)·109 M−1 s−1 (pH 6.0–8.0) for stavudine. A battery of ecotoxicological tests (i.e. inhibition growth, bioluminescence, mutagenic and genotoxic activity) using bacteria (Aliivibrio fischeri, Salmonella typhimurium), crustacean (Daphnia magna) and algae (Raphidocelis subcapitata) revealed a marked influence of the UV dose on the ecotoxicological activity. The UV254/H2O2 treatment process reduced the ecotoxicological risk associated to direct photolysis of the antiretrovirals aqueous solutions, but required significantly higher UV254 doses (≥2000 mJ cm−2) in comparison to common water UV disinfection processes

p-Type semiconducting properties in lithium-doped MgO single crystals

The phenomenally large enhancement in conductivity observed when Li-doped MgO crystals are oxidized at elevated temperatures was investigated by dc and ac electrical measurements in the temperature interval 250-673 K. The concentration of ([Li]^{0}) centers (Li^{+} ions each with a trapped hole) resulting from oxidation was monitored by optical absorption measurements. Both dc and ac experiments provide consistent values for the bulk resistance. The electricalconductivity of oxidized MgO:Li crystals increases linearly with the concentration of ([Li]^{0}) centers. The conductivity is thermally activated with an activation energy of (0.70 +/- 0.01) eV, which is independent of the ([Li]^{0}) content. The \textit{standard semiconducting} mechanism satisfactorily explains these results. Free holes are the main contribution to band conduction as they are trapped at or released from the ([Li]^{0})-acceptor centers. In as-grown MgO:Li crystals, electrical current increases dramatically with time due to the formation of ([Li]^{0}) centers. The activation energy values between 1.3 and 0.7 eV are likely a combination of the activation energy for the creation of ([Li]^{0}) centers and the activation energy of ionization of these centers. Destruction of ([Li]^{0}) centers can be induced in oxidized crystals by application of an electric field due to Joule heating up to temperatures at which ([Li]^{0}) centers are not stable.Comment: LaTeX, 20 pages, 9 Encapsulated Postscript Format Figures, use the version 4.0 of REVTEX 4 macro packag

Synthesis of Mg-Al layered double hydroxides by electrocoagulation

Recently, layered double hydroxides (LDHs) have attracted much consideration due to their versatility and easily manipulating properties and their potential applications such as anion exchangers, support of catalysts, flame retardants, biomedical drug delivery. A novel method for the in-situ preparation in situ of LDHs, using electrocoagulation (EC) processes was developed, the EC process was performed under two different conditions, at 5 mA m−2, changing polarity of the electrodes to find out the composition that leads to LDHs generation. The final product was characterized using XRD, BET and FTIR techniques. This method presented the following advantages: (1) Simultaneously LDHs synthesis and wastewater treatment by ion removal; (2) Polarity control allows to manipulate the M2+/M3+ molar ratio, LDHs properties and its potential applications; (3) The method spent less time to carry out the synthesis and; (4) it did not need complicated solid-liquid separation processes

Dataset on infrared spectroscopy and X-ray diffraction patterns of Mg–Al layered double hydroxides by the electrocoagulation technique

The XRD profiles and FTIR analysis of sludge aggregates, Mg–Al layered double hydroxides, produced during electrocoagulation processes are presented. The data describes the composition of materials (LDH) produced at different operations conditions (atmospheric conditions and Mg2+/Al3+ ratio). The data show the diffraction peaks of (003), (006), (018) and (110) crystal planes for hydrotalcite structure