Repetitive acoustic streaming patterns in sinusoidal shaped microchannels

Geometry of the fluid container plays a key role in the shape of acoustic streaming patterns. Inadvertent vortices can be troublesome in some cases, but if treated properly, the problem turns into a very useful parameter in acoustic tweezing or micromixing applications. In this paper, the effects of sinusoidal boundaries of a microchannel on acoustic streaming patterns are studied. Results show that while top and bottom sinusoidal walls are vertically actuated at the resonance frequency of basic hypothetical rectangular microchannel, some repetitive acoustic streaming patterns are recognized in classifiable cases. Such patterns can never be produced in rectangular geometry with flat boundaries. Relations between geometrical parameters and emerging acoustic streaming patterns lead us to propose formulas in order to predict more cases. Such results and formulations were not trivial at a glance

Pollen morphology of the genus Pyrus (Rosaceae) in Iran

In this study, pollen morphological characters of nine species of the genus Pyrus L. belonging to four sections, Argyromalon, Pashia, Pyrus and Xeropyrenia were examined by light (LM) and scanning electron (SEM) microscope. Regarding pollen shape, two forms can be recognized in the same specimen: the first form ranges from prolate- spheroidal, subprolate to prolate, while the second form includes triangular, trilobate and circular shapes, the apertures structure usually consists of three ectocolpi and three endopores. colpi occupy 85- 91% of length of pollen, often arranged meridionally but also parallel pattern can be recognized, endopore is located in the middle of colpi. Regarding sculpturing of the exine in proximal face, striate sculpturing is observed that according to some characters such as degree of slope of ridges, percentage of ridges and perforations, diameter of perforations is subdivided to four main types. Results of pollen grain fertility studies in the genus showed high percentage of fertility among studied species except in one species

Acridinium 3,5-dicarboxy­benzoate monohydrate

The title compound, C13H10N+·C9H5O6 −·H2O, exhibits a wide range of non-covalent inter­actions, such as O—H⋯O and N—H⋯O hydrogen bonds, π–π stacking [centroid-centroid distances = 3.562 (8) and 3.872 (8) Å] and ion pairing, connecting the various components into a supra­molecular structure

Use of lipophilic and hydrophilic polymers in production of sustained release zinc sulfate tablets

Background and aims: Zinc sulfate administered to correct zinc deficiency. Its oral administration has shown serious digestive side effects and sometimes it has led to the lack of use it. The main aim of the present study was to use lipophilic and hydrophilic polymers in production of sustained release zinc sulfate tabletsover an extended period of time. Methods: Sustained release (SR) zinc sulfate tablets were prepared using either lipophilic-based matrix or hydrophilic matrix system or natural polymers by either hot-fusion (HF) granulation or direct compression (DC) method. Physical and chemical features of provided SR tablets including hardness, friability, and weight variation, disintegration time, swelling index, content uniformity and drug release behavior were evaluated. The drug concentration was assayed by an atomic absorption spectrophotometer at 213.8 nm. Results: Most of the prepared formulations showed acceptable physicochemical properties. Among 30 formulations, SR tablets with lipophilic matrix-based showed more predictable release profiles compared to tablets prepared based on hydrophilic or natural matrixes. Tablets containing carnauba wax showed slower release while tablets with hydrogenated castor oil represented faster release profile. A few lipophilic matrix tablets containing zinc sulfate (110 mg), beeswax (or carnauba wax) and Avicel (or Emcompress) were selected as the optimum formulations showing release profiles based on USP criteria for lipophilic-based SR tablets. The mean dissolution time (MDT) and dissolution efficiency (DE8%) of selected formulations were 1.69-1.95 hr and 69.3-71.8%, respectively. Tablet hardness and granule size had no effects on release rate. The drug release kinetic followed Higuchi model. Conclusion: Lipophilic based SR tablets of zinc sulfate is suggested as an alternative for capsule or syrup of the drug whichhave digestive side effects

Development and validation of a HPTLC method for analysis of Sunitinib malate

A simple high performance thin layer chromatography (HPTLC) has been developed and validated for determination of sunitinib malate and possible impurities. The samples were applied in forms of bands on an aluminum TLC plate pre-coated with silica gel and were separated using dichloromethane: methanol: toluene: ammonia solution as the mobile phase. Sunitinib malate was thoroughly separated from impurities including E-isomer, sunitinib N-oxide and impurity B with a retention factor (RF) of 0.35±0.02. Quantitative analysis of sunitinib was carried out using a mobile phase consisting of dichloromethane:methanol:ammonia solution, RF value was 0.53±0.02 for Z isomer. Detection was performed densitometrically in absorbance mode at 430 nm. This method was found to produce sharp, symmetrical, and well resolved peaks. Linear relationship with the coefficients of determination >; 0.99 was achieved over the concentration range of 27.34 to 437.5 ng/spot. This method provides robust, replicable and accurate results with acceptable sensitivity

Hydroxonium creatininium bis­(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)cobaltate(II) trihydrate

The title compound, (C4H8N3O)(H3O)[Co(C7H3NO4)2]·3H2O, contains a protonated creatininium cation, a hydrox­onium (H3O)+ cation, a [Co(pydc)2]2− (pydcH2 = pyridine-2,6-dicarboxylic acid) complex anion, and three uncoordinated water mol­ecules. The CoII atom is coordinated by four O and two N atoms from two pydc ligands in a distorted octa­hedral environment. The structure also contains three uncoordinated water mol­ecules. Extensive inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, π–π stacking inter­actions [centroid–centroid distances = 3.565 (14) and 3.425 (14) Å] and O⋯π inter­actions [O⋯centroid distance = 3.480 (2) Å] connect the various components in the crystal structure

(3-Amino­phen­yl)diphenyl­phosphine oxide–2-propanol (1/1)

The title compound, C18H16NOP·C3H8O, was synthesized by the reduction of (3-nitro­phen­yl)diphenyl­phosphine oxide in the presence of 2-propanol as recrystallization solvent. There are two molecules in the asymmetric unit. Each P atom is tetra­coordinated by three C and one O atom from two phenyl fragments, one aniline group and one double-bonded O atom in a distorted tetra­hedral geometry. C—H⋯π and N—H⋯π inter­actions are present. In the crystal structure, a wide range of non-covalent inter­actions consisting of hydrogen bonding [of the types of O—H⋯O, N—H⋯O and C—H⋯O, with D⋯A distances ranging from 2.680 (3) to 3.478 (3) Å] and π–π [centroid–centroid distance of 3.7720 (15) Å] stacking inter­actions connect the various components into a supra­molecular structure

Parallel APSM for Fast and Adaptive Digital SIC in Full-Duplex Transceivers with Nonlinearity

This paper presents a kernel-based adaptive filter that is applied for the digital domain self-interference cancellation (SIC) in a transceiver operating in full-duplex (FD) mode. In FD, the benefit of simultaneous transmission and receiving of signals comes at the price of strong self-interference (SI). In this work, we are primarily interested in suppressing the SI using an adaptive filter namely adaptive projected subgradient method (APSM) in a reproducing kernel Hilbert space (RKHS) of functions. Using the projection concept as a powerful tool, APSM is used to model and consequently remove the SI. A low-complexity and fast-tracking algorithm is provided taking advantage of parallel projections as well as the kernel trick in RKHS. The performance of the proposed method is evaluated on real measurement data. The method illustrates the good performance of the proposed adaptive filter, compared to the known popular benchmarks. They demonstrate that the kernel-based algorithm achieves a favorable level of digital SIC while enabling parallel computation-based implementation within a rich and nonlinear function space, thanks to the employed adaptive filtering method

Poly[piperazinediium [aqua­bis(μ-pyridine-2,5-dicarboxyl­ato)zincate] dihydrate]

The polymeric title compound, {(C4H12N2)[Zn(C7H3NO4)2(H2O)]·2H2O}n, was obtained by the reaction of zinc(II) nitrate hexa­hydrate with the proton-transfer compound (pipzH2)(py-2,5-dc) (where pipz is piperazine and py-2,5-dcH2 is pyridine-2,5-dicarboxylic acid) in aqueous solution. Each ZnII atom is coordinated in a distorted octa­hedral geometry by four O atoms and two N atoms from one water mol­ecule and two (py-2,5-dc)2– ligands, which also act as bridging ligands between ZnII atoms. π–π Stacking inter­actions between two aromatic rings of (py-2,5-dc)2– fragments, with centroid–centroid distances of 3.4747 (7) and 3.7081 (7) Å are observed. The crystal structure is stabilized by O—H⋯O and N—H⋯O hydrogen bonds