Melting Point Of Crystal Research Articles

Surface and Subsurface Quality Assessment of Polished Lu2O3 Single Crystal Using Quasi-Brewster Angle Technique

The sesquioxide Lu2O3 single crystal has attracted tremendous attention as potential host material for high-power solid-state lasers. As polishing is the terminal process of conventional ultra-precision machining, the quality of polished crystal directly impacts the crucial performance indicators of optics. The high melting point of Lu2O3 single crystal makes crystal preparation difficult. Therefore, investigations on the surface/subsurface quality inspection of polished Lu2O3 single crystal are scarce. In this paper, we utilize the quasi-Brewster angle technique (qBAT) based on ellipsometry to inspect the quality of polished Lu2O3 single crystal, achieving fast, non-destructive, and high-sensitive surface/subsurface damage assessment. A systematic crystal processing scheme is designed and polished Lu2O3 crystal samples are obtained. To verify the results of qBAT, the surface and subsurface quality are tested using optical profilometer and transmission electron microscope, respectively. The consistency of the test results demonstrates the feasibility, high sensitivity, and accuracy of the qBAT. To our knowledge, this is the first time that the qBAT is applied to investigate the polished surface/subsurface quality of Lu2O3 single crystal. In conclusion, this method provides a powerful approach to the high-precision characterization of the surface/subsurface quality of Lu2O3 single crystal, and has significant potential for material property study and process optimization during ultra-precision machining.

One-pot synthesis of N-benzyl-2-aminobenzoic acid, via ring opening of isatoic anhydride derivative, and its antibacterial screening

2-(N-Benzyl) amino benzoic acid is a bifunctional molecule that could be produced from the reaction between isatoic anhydride and aryl halide. Analogues and derivatives of isatoic anhydride have wide application in pharmaceuticalsincluding antibacterial activity. The aim of this study is to synthesize, characterize and screen N-benzyl isatoic anhydride and 2-(N-benzyl) amino benzoic acid for antibacterial activity. The reaction of isatoic anhydride and benzyl bromide in the presence of potassium carbonate in DMSO at room temperature yielded N-benzyl isatoic anhydride, which under hydrolysis yielded 2-(N-benzyl) amino benzoic acid in which the anhydride ring is opened up. This compound was screened against Gram positive and negative bacteria. Moderate yield of 2-(N-benzyl) amino benzoic acid, a yellow crystal (melting point of 160-162oC, percentage yield 65 %, Rf 0.19) formed by ring opening of N-benzyl isatoic anhydride. The compound showed no antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas pyocyanea, Salmonella typhimurium, Klebsiella aeruginosa and Bacillus subtilis. 2-(N-benzyl)amino benzoic was synthesized, characterized and showed no activity against bacteria.

On prediction of melting points without computer simulation: A focus on energetic molecular crystals

Melting point is one of the most important characteristics for molecular engineering of energetic materials. Therefore, methods for prediction of this physical property are essential to the field. In this paper, we have developed two models for prediction of melting point of energetic molecular crystals. The first one uses two parameters (lattice energy and crystal density) and grounds on the correlation of 200 compounds. The second model does not use any calculated quantities (only tabulated data) and is based on 1500 compounds. The first model needs separate calibrations for specific families of compounds; for nitroaromatic compounds, aliphatic nitro- and nitrato compounds and peroxides it provides R2 = 0.82–0.85 and RMSE ≥ 21–54 °C, respectively. Meanwhile, Model 2 is a more universal, but less accurate approach and it was tested for 747 energetic materials of different families providing R2 = 0.62 and RMSE ≥ 64 °C. This makes Model 2 a simple and convenient tool for a fast crude estimation of melting point of a desired energetic molecular crystal using a pocket calculator. Since Model 2 does not need quantum-chemical calculations, it can be effectively applied for any arbitrary composition. In the present work, however, we have considered compounds with a restricted number of constituting elements: C–H–N–O–S–F–Cl–Br–I. Nevertheless, extension of Model 2 is a simple procedure, which assumes estimation of so-called effective densities for other elements via regression analysis of experimentally available data on melting points.

Experimental and theoretical studies on bis (6-nitroquinoline) fumaric acid co-crystal

6-Nitroquinoline fumaric acid (C11H8N2O4), an organic co-crystal is grown using slow evaporation solution growth technique. The grown crystal is characterized by single crystal X-ray diffraction (SCXRD) and the title compound is crystallized in monoclinic crystal system with P21/n centrosymmetric space group. The OH···N and CH···O hydrogen bonds influence heterodimer formation in the crystal structure. The optical absorption spectrum of the title compound shows an absorption peak at 333 nm which contributes to π→π* transition. The transmission spectrum shows about 82% transparency in the visible region with lower cutoff wavelength 370 nm. The vibrational modes and assignments of functional groups are done using FTIR and Raman spectroscopic analyses. The CO stretching is the most characteristic vibration of the carboxylic acid group and it typically appears at 1393 cm−1. The thermal behavior of the present compound is evaluated by TG/DSC techniques and the melting point of the title crystal is 191 °C. The finger print plots show that H···O (41.9%) interactions are dominated interactions. These interactions are responsible for CH···O hydrogen bonds which play vital role in the structure stabilization. The first order hyperpolarizability value is calculated using B3LYP method with the extended 6–311++G(d,p) basis set and it is found as 4.5 times larger than that of urea.

Synthesis, growth, spectral and computational studies on aminomethylpyridinium trichloroacetate single crystal

The molecular compounds 2-amino-6-methylpyridine and trichloroacetic acid were synthesized in the ratio 1:1 and a single crystal aminomethylpyridinium trichloroacetate (AMPTA) was grown with the base compound 2-amino-6-methylpyridine (2AMP) as a donor and the acid compound trichloroacetic acid (TA) functions as an acceptor. The modes of vibration with the functional group was investigated from the analysis of FTIR spectroscopy. The existence of proton was prognosticated by 1H NMR spectral analysis. The π→π∗ transition shifted to wavelength 310 nm in UV–vis-NIR spectra confirms the emergence of the AMPTA crystal. The percentage of transmittance spectrum showed the suitability of the compound for non-linear optical applications. TG-DTA analysis was done to study the thermal stability and the melting point of AMPTA crystal was assessed through thermogravimetry (TG) and differential thermal analysis (DTA). The density functional theoretical method (DFT) was carried out with the help of the B3LYP/3-21G(d,p) basis set, and the results were compared with the experimental values.

Preparation and growth mechanism of micro spherical ammonium dinitramide crystal based on ultrasound-assisted solvent-antisolvent method

Micro-sized spherical ammonium dinitramide (ADN) crystals are successfully prepared by a facile ultrasound-assisted solvent-antisolvent recrystallization method without introducing any additives. The influences of the volume ratio of solvent to antisolvent, the antisolvent temperature and the ultrasound power on the micro-morphologies and properties of ADN crystals are studied systematically. The changes of morphology, particle size, crystal structure and melting point of the ADN crystals are characterized through scanning electron microscopy (SEM), laser particle size analyzer (LPSA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The results show that the optimal experimental parameters for the ADN crystal of spherical morphology are as follows: the volume ratio of solvent to antisolvent is 1:50, the antisolvent temperature is 20 ℃, and the ultrasound power is 70 W. The predicted hexagonal-flake and spherical morphologies for the ADN are close to the experimental morphologies. The growth mechanism of the spherical ADN crystal changes with supersaturation of the ADN solution. As the degree of supersaturation increases, the growth models of the spherical ADN change from the spiral growth to the rough growth, and the morphologies of ADN change from the large-sized ADN ball to the small-sized ADN ball.

A novel drug delivery system —— Drug crystallization encapsulated liquid crystal emulsion

Liquid crystals (LCs) are widely used for drug delivery due to their controlled and sustained drug release properties. In this paper, drug crystallization encapsulated liquid crystal emulsion, a novel drug delivery system, was proposed. The lamellar liquid crystals formed by hydrogenated lecithin, which are similar to the skin stratum corneum lipid structure, are adopted as the drug carrier to encapsulate non-steroidal anti-inflammatory drugs (NSAIDs). As the model drug, ketoprofen exists in the hydrophobic core of emulsion as a drug crystal when squalane is used as the oil phase. The microstructure, sustained drug release behaviors, physicochemical property and biocompatibility of the system were examined by polarized light microscopy, rheological measurements, differential scanning calorimetry, X-ray diffraction, small-angle X-ray scattering, in vitro release study, and in vitro cellular cytotoxicity assay. The results have shown that the novel system lowers the drug crystal melting point and improves the thermal stability of liquid crystal structure. Besides, the excellent biocompatibility and sustained release property through the additional dissolution step of drug crystal show its application potentials in the topical cosmeceuticals. The results will also be helpful for in-depth understanding of the physical state of encapsulated drug in the liquid crystal carrier systems.

Enhancing solubility and antibacterial activity using multi-component crystals of trimethoprim and malic acid

Aim: To improve the solubility and antibacterial activity of trimethoprim (TMP) by preparing its multicomponent crystals with malic acid (MA). 
 Methods: Multicomponent crystals of TMP-MA were prepared by solvent co-evaporation. The solid-state properties were characterised by powder X-ray diffraction (PXRD), differential thermal analysis (DTA), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) analyses. The solubility was investigated in an aqueous medium, while the antibacterial activity against Escherichia coli was investigated using the agar disk diffusion method. 
 Results: The PXRD pattern of the TMP-MA binary system differed from the starting materials, supporting the formation of a new crystalline phase (equimolar ratio). The DTA thermogram showed a single, sharp, endothermic peak at 212.5 °C attributable to the TMP-MA multicomponent crystal's melting point. FT-IR spectroscopy showed a solid-state interaction involving proton transfer between TMP and MA. The multicomponent crystal displayed a 2.5-fold higher solubility and had increased antibacterial activity compared to TMP alone. 
 Conclusions: The TMP-MA binary system forms salt-type multicomponent crystals that significantly increase solubility and antibacterial activity. Multicomponent crystal formation is a viable technique for modifying the physicochemical properties of active pharmaceutical ingredients.

Growth, crystal structure, thermal, spectral studies and density functional theory computational analysis of an organic nonlinear optical crystal: 2‐{3‐[2‐(4‐dimethylaminophenyl)vinyl]‐5,5‐dimethylcyclohex‐2‐enylidene}‐malonitrile

AbstractWe report on synthesis, growth and characterization of an organic nonlinear optical (NLO) crystal 2‐{3‐[2‐(4‐dimethylaminophenylvinyl]‐5,5‐dimethylcyclohex‐2‐enylidene}‐malonitrile (DAT2). The functional groups are identified by 1H‐NMR. Large size single crystal of DAT2 of size 1.2 × 0.5 × 0.2 cm3 is grown for the first time using solution growth technique. The physicochemical properties of DAT2 crystal such as crystal structure, melting point, optical reflectance and photoluminescence are studied experimentally. Density functional theory (DFT) analysis is employed to study the band structure, optical and electronic properties of DAT2. The theoretical bandgap was compared with the experimental one. LDA approximation has been used to compare the GGA results.

KARAKTERISASI SENYAWA ANALGETIKA-ANTIINFLAMASI N-(4t-BUTILBENZOIL)-p-AMINOFENOL YANG DISINTISES DENGAN KATALIS ASAM

The N-(4t-Butylbenzoyl)-p-Aminophenol compound was a synthesis compound between p-aminophenol and 4t-Butylbenzoyl chloride by using H2SO4 catalyst. The addition of H2SO4 catalyst purposed to accelerate the rate of rection in the synthesis of the compound and increased yield of product. The N-(4t-Butylbenzoil)-p-Aminophenol compound is beneficial as an antiinflammatory analgesic. This research were proposed to determine characteristics of the anti-inflammatory analgesic synthesis of N-(4t-Butylbenzoyl)-p-Aminophenol compound by using H2SO4 catalyst. Characterization conducted in this research were physical and chemical characterization. The physical characterization were organoleptic test, crystal form test and melting point test. While chemical characterization were UV-Vis spectrophotometry and FTIR. Result of organoleptic test showed sample had powder form, white-gray colour and not taste. Melting point of N-(4t-Butylbenzoyl)-p-Aminophenol compound was 193.33 °C. The optimum wavelength of UV-Vis spectrophotometry got 2 peaks at the wavelengths 290 and 295 nm. The result of FTIR showed that N-(4t-Butylbenzoyl)-p-Aminophenol compound had peaks.Keywords: N-(4t-butyl benzoil)-p-aminophenol, catalyst

A theoretical investigation into the cooperativity effect on the TNT melting point under external electric field.

External electric field has been regarded as an effective tool to induce the variation of melting points of molecular crystals. The melting point of 2,4,6-trinitrotoluene (TNT) was calculated by molecular dynamics simulations under external electric field, and the electric field effects on the cooperativity effects of the ternary (TNT)3 were investigated at the M06-2X/6-311+G(d) and ωB97X-D/6-311++G(2d,p) levels. The results show that the melting points are decreased while the intermolecular interactions are strengthened under the external electric fields, suggesting that the intermolecular interactions cannot be used to explain the decreased melting points. A deduction based on the cooperativity effect is put forward: the enhanced cooperativity effects create the more serious defects in the melting process of the molecular crystal under the external electric fields, and simultaneously the local order parameters are decreased, leading to the decreased melting point. Thus, the cooperativity effect stemmed from the intermolecular C-H∙∙∙O H-bonding interactions controls the change of TNT melting point under the external electric field. Employing the information-theoretic approach (ITA), the origin of the cooperativity effects on the melting points of molecular crystal is revealed. This study opens a new way to challenge the problems involving the melting points for the molecular crystal under the external electric fields. However, note that above deduction needs to be improved; after all, the simple (TNT)3 model cannot replace the crystal structure.

Molecular dynamics simulations of helium migration, diffusion behavior of helium bubbles, and melting point of single crystal in bulk γ-Fe

The behavior of He atoms in γ-Fe single crystal is studied using the molecular dynamics simulation (MD) methods. Simulations show that the melting point of bulk γ-Fe computed by single-phase and dual-phase methods is 1935 and 1727 ± 1 K, respectively. There is evidence that the diffusion of He clusters is closely related to the cluster size and temperature and at high temperatures (above 1500 K), large clusters will break up into small clusters and quickly separate from the original clusters. The study on the diffusion behaviors of He clusters helps us to better understand the formation of He bubbles and the fusion of two He bubbles. It was confirmed that the He atom can migrate to the subsurface, but it is difficult to escape from the surface and diffuse to the vacuum slab. This work provides useful information for further theoretical and experimental research on the evolution behaviors of He in materials.

Effects of Doped Elements (Si, Cr, W and Nb) on the Stability, Mechanical Properties and Electronic Structures of MoAlB Phase by the First-Principles Calculation.

First-principles calculations based on density functional theory (DFT) have been performed to explore the effects of Si, Cr, W, and Nb elements on the stability, mechanical properties, and electronic structures of MoAlB ternary boride. The five crystals, with the formulas of Mo4Al4B4, Mo4Al3SiB4, Mo3CrAl4B4, Mo3WAl4B4, and Mo3NbAl4B4, have been respectively established. All the calculated crystals are thermodynamically stable, according to the negative cohesive energy and formation enthalpy. By the calculation of elastic constants, the mechanical moduli and ductility evolutions of MoAlB with elemental doping can be further estimated, with the aid of B/G and Poisson’s ratios. Si and W doping cannot only enhance the Young’s modulus of MoAlB, but also improve the ductility to some degree. Simultaneously, the elastic moduli of MoAlB are supposed to become more isotropic after Si and W addition. However, Cr and Nb doping plays a negative role in ameliorating the mechanical properties. Through the analysis of electronic structures and chemical bonding, the evolutions of chemical bondings can be disclosed with the addition of dopant. The enhancement of B-B, Al/Si-B, and Al/Si-Mo bondings takes place after Si substitution, and W addition apparently intensifies the bonding with B and Al. In this case, the strengthening of chemical bonding after Si and W doping exactly accounts for the improvement of mechanical properties of MoAlB. Additionally, Si doping can also improve the Debye temperature and melting point of the MoAlB crystal. Overall, Si element is predicted to be the optimized dopant to ameliorate the mechanical properties of MoAlB.

Thermo-responsive shape memory effect in isotactic propylene/1-butene copolymers

This paper reported a thermo-responsive shape memory effect in common isotactic propylene/1-butene copolymer (iPPBu) synthesized by Ziegler-Natta catalyst. The deformation principle in the copolymer was cold deformation, and the recovery temperature was around 60 °C, giving the recovery ratio Rr as high as 80%. After a cold deformation, the copolymer could return to the original shape at about 60 °C, with a recovery ratio Rr of up to 80%. The crystal structures of the copolymer during deformation and recovery were investigated by WAXS measurements, and the shape memory effect mechanism in such materials was proposed. The mechanism varied according to the copolymer composition, but the crystal transformation always played a key role in the shape memory behavior. iPPBus with about 30–60 mol% of 1-butene exhibited unique crystal transition from isotactic polypropylene (iPP) α form to iPP trigonal form under stretching, which rendered the materials with fixing ratio Rf of 70–80% and relatively stable recovery ratio Rr of 65–80% at 60 °C owing to the constant melting point of trigonal crystal. This work provided a potential application of these common propylene copolymers in shape memory materials.

Physicochemical Properties of Xylitol Crystals from Oil Palm Empty Fruit Bunches Hydrolysate

Xylitol, a low-calorie sugar made up of five carbon atoms, had the valuable characteristics suitably applied for pharmaceutical and food industries. This sugar can be produced from oil palm empty fruit bunches (OPEFB) through hydrolysis and followed by fermentation. The xylitol in the fermentation broth requires the downstream process to obtain the final product with high purity and yield. Among a series of xylitol downstream process, crystallization becomes a critical step since this process determines the properties of final products. The objective of this study was to evaluate the effect of evaporation temperature (55°C and 70°C) and seeding addition (0%, 0.1%, 0.5%, 1 %) in the crystallization step on the physicochemical properties of xylitol crystals obtained from the OPEFB hydrolysate. The main evaluation criteria were crystal contents, purity, melting point, water content, hygroscopicity, solubility, caloric content, and crystal xylitol yield. The result showed that the crystal form obtained was relatively sticky and had lower purity than commercial ones because the concentration of xylitol solution increased after evaporation. The differences of physicochemical properties of the crystals such as the purity, porosity, yield and crystal form were influenced by evaporation temperature. The crystals formed by 70°C evaporation temperature produced the crystals with higher caloric value and purity, but it had lower hygroscopicity and moisture content than crystals formed by 55°C. However, the percentage of seeding gave an insignificant impact on xylitol crystal properties.

Generation of Amorphous Silicon Dioxide Structures via Melting-Quenching Density Functional Modeling

Ab initio quantum molecular dynamics simulation is used to transform a silicon dioxide crystal into silica amorphous states. Two type of amorphous states are obtained from the melts stabilized at temperatures well above the crystal melting point. The first type of amorphous states are obtained from the melts stabilized at comparably low temperatures of $$3000$$ and $$4000$$ K. These states are characterized by a perfect structure similar to those of the initial crystal and vitreous silica glass without point defects. Completely different amorphous states are obtained from the high temperature melts of $$5000$$ and $$6000$$ K. Structures of these amorphous states are less regular and contain point defects of silicon dioxide such as over-coordinated fivefold silicon, threefold oxygen atoms and a new silica defect 2-Bridging Oxygen Center. The latter is detected in the model of amorphous silica for the first time and it is formed by two neighbouring $$SiO_{4}$$ -tetrahedra with two common oxygen vertexes. The amorphous silica models can be useful for description of amorphous silicon dioxide films obtained by high energy ion-beam deposition process where a fast local melting-quenching process should exist.

PREFORMULATION STUDIES OF PILOCARPINE HYDROCHLORIDE AS NIOSOMAL GELS FOR OCULAR DRUG DELIVERY

Objective: Pilocarpine hydrochloride is a direct acting cholinergic parasympathomimetic agent which directly stimulates cholinergic receptor (M3). It is a drug used in the treatment of chronic open-angle glaucoma for over 100 years. Designing a new ophthalmic dosage form for pilocarpine hydrochloride compels performing preformulation studies for drug. Therefore, the current aim of the study was to investigate some of the important physicochemical properties of pilocarpine hydrochloride which can help to select subsequent approaches during the development of niosomal gel for ocular use.
 Methods: Preformulation studies of drug were carried out for identification (physical appearance, melting point, and UV spectrophotometric analysis), solubility profile, lipophilicity (partition coefficient), compatibility studies by Fourier-transform infrared (FTIR) spectroscopy, and thermal behavior by differential scanning calorimetry (DSC).
 Results: The melting point of pilocarpine hydrochloride was found to be 204 ± 3○C. The log P value was found to be 1.12 ± 0.02, from which it can be interpreted that drug is highly hydrophilic in nature. The scanned λmax was found to be 215 nm. No significant changes were found when FTIR spectra of physical mixture compared with FTIR spectra of pure drug and excipients. This indicates absence of any possible interaction between the drug and excipients which confirms the identity and purity of drug. DSC thermogram of pure drug showed a sharp exothermic peak at 191.923○C (area=68.890 mJ, delta H = 22.963 J/g), indicating the crystal melting point of the drug.
 Conclusion: These results suggest that the pilocarpine hydrochloride serves as suitable candidate for ocular drug delivery system.

Optical, Thermal Properties of Cadmium Chloride Reinforced PVA:PVP Blend Films

In this study, pure polymer blend film (PVA:PVP) and salt (CdCl 2 .H 2 O) reinforced polymer blend films were prepared at different weight ratios (10, 20, 30) wt% using the casting method. The optical and thermal properties of all polymer blend films were studied.The transmittance and absorbance spectra were recorded within the wavelength range (190-1100) nm. The effect of salt weight ratio on the energy gap of salt (CdCl 2 .H 2 O) reinforced polymer blend films (PVA:PVP) was studied, and it was found that the energy gap decreases as the salt (CdCl 2 .H 2 O) weight ratio increases. The results showed that electronic transitions are indirect. The effect of salt weight ratio on the thermal properties of the polymer blend films (PVA:PVP) reinforced by (CdCl 2 .H 2 O) salt of the polymer blend based reinforced by (CdCl 2 .H 2 O) salt were also studied. The experimental results showed that the thermal conductivity coefficient of the polymer blend films (PVA:PVP) reinforced by (CdCl 2 .H 2 O) salt increases and then decreases irregularly as the weight ratio of the salt (CdCl 2 .H 2 O) increases, and it is found that the thermal conductivity coefficient polymer blend is very small for all weight ratios and therefore they can be used as a heat-insulation shields. The value of the glass transition temperature, crystal melting point and crystallinity of the polymer blend films (PVA:PVP) reinforced by (CdCl 2 .H 2 O) salt vary with the increase in salt (CdCl 2 .H 2 O) weight ratios, noting the disappearance of crystallization for the pure (PVA:PVP) polymer blend film, reinforced polymer blend films at certain weight ratios of the salt (CdCl 2 .H 2 O).

New insights into the memory effect on the crystallization behavior of poly(phenylene sulfide)

In this article, the melt and crystallization kinetics of poly(phenylene sulfide) (PPS) powder was studied by differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR) and polarized optical microscopy (POM). It is found that the folded-chain crystals of PPS (melting point at 281 °C) could be erased at about 350 °C, while the equilibrium melting point of extended-chain crystals (melting point at 295 °C) is 370 °C. Although the residual nuclei could be eliminated completely at 370 °C, the spherulite growth rate of PPS during crystallization keeps accelerating with the increasing melting relaxation time, resulting from the transformation of the lamellae and the amorphous cluster to an ordered structure with low entanglement density. Furthermore, due to the restricted chain mobility for the semi-flexible PPS, this unique memory effect would survive in the whole manufacturing process, resulting in the varying results from different researches and the significant influence on the processability and performance of PPS products.

Cyclohexylammonium Cinnamate Single Crystal for Nonlinear Optical Applications

Slow evaporation technique has been employed to grow single crystals of cyclohexylammonium cinnamate (CYHC). The presence of functional groups was analyzed via Fourier transform infrared spectroscopy, and the single-crystal x-ray diffraction analysis confirmed P21/n symmetry in the crystal. Thermal analysis confirmed the melting point of the single crystal at 175.12°C and decomposition mechanism. The dielectric studies of CYHC were analyzed, and the activation energy of the sample was also estimated. The photoluminescence (PL) spectrum of CYHC shows the emission wavelength at 500 nm (green emission region), and chemical etching studies were carried out to investigate the surface quality of CYHC crystal. Third-order nonlinear and optical limiting studies were performed, and the values of threshold output and clamping output were found to be 18.62 mW and 1.72 mW, respectively.