Finite element program for flight structure analysis

Summary A computer program is developed for the analysis of large complex structures of any kind but especially for those used in flight vehicles.The displacement method chosen, using the finite element algorithm and the related matrix calculation, allows a high degree of automation in the data processing, the human intervention being confined to introducing the topoelastic quantities that are essential to the correct definition of the structural problem.The program is organized in such a way as to allow subsequent developments including, on the initial basis, dynamic and non linear effects.Given the contained calculating times and limited occupation of the core storage, the program can be used on medium-sized computers.

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Sommario Viene presentato lo sviluppo di un programma di calcolo per la verifica di strutture grandi e complesse di qualsiasi tipo, ma con particolare riguardo a quelle impiegate nelle costruzioni aerospaziali, mediante l'uso di un elaboratore elettronico.Il metodo deformazionale scelto, sfruttando l'algoritmo degli elementi finiti ed il connesso calcolo matriciale, permette un elevato grado di automazione nell'elaborazione dei dati, tale da limitare l'intervento umano alla sola introduzione delle grandezze topoelastiche che siano essenziali alla corretta definizione del problema strutturale.Il programma è organizzato in modo da permettere sviluppi successivi, fino ad includere, sulla base iniziale, effetti dinamici e non lineari.I tempi di calcolo contenuti e la limitata occupazione di memoria operativa ne estendono l'impiego a calcolatori di media dimensione.

     

Facile Synthesis of a Furan–Arylamine Hole‐Transporting Material for High‐Efficiency,Mesoscopic Perovskite Solar Cells

A novel hole‐transporting molecule (F101) based on a furan core has been synthesized by means of a short, high‐yielding route. When used as the hole‐transporting material (HTM) in mesoporous methylammonium lead halide perovskite solar cells (PSCs) it produced better device performance than the current state‐of‐the‐art HTM 2,2′,7,7′‐tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD). The F101‐HTM‐based device exhibited both slightly higher J_sc (19.63 vs. 18.41 mA cm^?2) and V_oc (1.1 vs. 1.05 V) resulting in a marginally higher power conversion efficiency (PCE) (13.1 vs. 13 %). The steady‐state and time‐resolved photoluminescence show that F101 has significant charge extraction ability. The simple molecular structure, short synthesis route with high yield and better performance in devices makes F101 an excellent candidate for replacing the expensive spiro‐OMeTAD as HTM in PSCs.     

A fast route for the synthesis of tetrazolyl oximes by a novel multicomponent reaction between Z-chlorooximes,isocyanides and trimethylsilyl azide

A library of twenty variously decorated 1,5-disubstituted-(1H-tetrazol-5-yl)methanone oximes was prepared in one single synthetic step exploiting the combination of (Z)-chlorooximes, isocyanides and trimethylsilyl azide. The formal [3+1] cycloaddition between isocyanides and nitrile N-oxides with respect to the [3+1] cycloaddition between isocyanides and azides prevails, while the direct attack of azide onto nitrile N-oxides remains competitive. Finally, an intramolecular cyclization of a (1H-tetrazol-5-yl)methanone oxime to a benzoisoxazole tetrazole is reported for the first time.     

A Convenient Synthesis of Phosphate Esters of Dopamine and Epinine

The title compounds were prepared with a route which is characterized by the regioselective preparation of 3 or 4 oxydryl protected dopamine and epinine precursors.     

t-Butyl Hypochlorite: A Powerful Electrophilic Aromatic Ring Chlorinating Agent

t-Butyl hypochlorite is an excellent aromatic ring chlorinating agent, under mild conditions, without any catalyst, of acetanilide. High regioselectivity is observed, the product being, nearly exclusively, para-chloroacetanilide.     

A Convenient Synthesis of 9-Hydroxy-3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indole from 7-Methoxyindole

The title compound was prepared with a route which is characterized by selective carboxylation in position four of 7-methoxyindole. Brief biological results are reported.     

Synthesis,NMR Study and Preliminary Sorption Properties of two N-Benzyl Sulfonated Chitosan Derivatives 1

Abstract

Two chitosan based sorbents for the uptake of metallic cations in acidic solutions were synthesized. Chitosan was reacted with 2-formylbenzene sodium sulfonate and 4-formyl-1,3-benzene sodium disulfonate in the presence of NaCNBH₃ to yield N-benzyl mono and disulfonate derivatives of chitosan. NMR spectra confirmed the presence of benzyl sulfonate groups which were subsequently used to determine the degree of substitution. The results of sorption experiments for mono and divalent metals at pH=2 are reported.

     

Chemical Approaches for Studying the Biology and Pharmacology of Membrane Transporters: The Histidine/Large Amino Acid Transporter SLC7A5 as a Benchmark

The localization of membrane transporters at the forefront of natural barriers makes these proteins very interesting due to their involvement in the absorption and distribution of nutrients and xenobiotics, including drugs. Over the years, structure/function relationship studies have been performed employing several strategies, including chemical modification of exposed amino acid residues. These approaches are very meaningful when applied to membrane transporters, given that these proteins are characterized by both hydrophobic and hydrophilic domains with a different degree of accessibility to employed chemicals. Besides basic features, the chemical targeting approaches can disclose information useful for pharmacological applications as well. An eminent example of this picture is the histidine/large amino acid transporter SLC7A5, known as LAT1 (Large Amino Acid Transporter 1). This protein is crucial in cell life because it is responsible for mediating the absorption and distribution of essential amino acids in peculiar body districts, such as the blood brain barrier and placenta. Furthermore, LAT1 can recognize a large variety of molecules of pharmacological interest and is also considered a hot target for drugs due to its over-expression in virtually all human cancers. Therefore, it is not surprising that the chemical targeting approach, coupled with bioinformatics, site-directed mutagenesis and transport assays, proved fundamental in describing features of LAT1 such as the substrate binding site, regulatory domains and interactions with drugs that will be discussed in this review. The results on LAT1 can be considered to have general applicability to other transporters linked with human diseases.