Atomic Weight Ratio Research Articles

Radiocarbon dating of bones from archeological site Târgșoru Vechi

The early medieval settlement identified in 2019 on the west side of Târgșoru Vechi is one of the largest settlements so far investigated in Wallachia, dating from the end of the first millennium AD. Sampling for radiocarbon analysis was done from inside the houses (especially in the area of the fireplace), from the graves, as well as from one of the possible wells. Supplementary samples were also taken from a group of tombs (west-east oriented) previously studied. In this study, several pretreatment methods were applied to historical bones and teeth from the Târgșoru Vechi site, in order to remove different contaminants to ensure accurate AMS analysis. The C/N atomic weight ratio of the untreated and pretreated bones was observed to be a useful indicator for the most suitable processing method. After collagen was extracted, in the RoAMS laboratory from IFIN-HH, it was graphitized using the Automated Graphitization Equipment (AGE3) and the isotopic ratios 14C/12C, 13C/12C were measured with the 1MV Tandetron Accelerator. The radiocarbon age was in the estimated archaeological range between 1114 and 1256BP. After calendar ages were obtained, using the IntCal20 calibration curve the placement of the studied archeological site in time was confirmed, which paves the way for an extensive Târgșoru Vechi site investigation.

Preparation and properties of nickel site doped material Ni1-yXyCo2O4 as supercapacitor materials by in-situ growth method

Although NiCo2O4 has been widely applied in supercapacitors, its actual capacity has been limited by the low conductivity and reactivity. Due to the relationship between the performance of the spinel-structured NiCo2O4 electrode material and its microstructure, in this paper, in order to modify the nanostructure of NiCo2O4 to improve its electrochemical performance, hydrothermal method is adopted to synthesize Ni0.98X0.02Co2O4(X = Fe, Cu, Mg, V, Ag, Mn, Mo, Ti) grown on nickel foam. After the synthesis, the physical morphology of the selected Ni0.98Mg0.02Co2O4 and Ni0.98Mn0.02Co2O4 are tested and analyzed by XRD, SEM, XPS and FT-IR. According to the characterization results, it can be found that different kinds of metals are doped in the nickel site of NiCo2O4, and the microscopic morphology of materials is different. It can be seen from the SEM figure that Ni0.98Mg0.02Co2O4 is a small nano-scale particle, while Ni0.98Mn0.02Co2O4 presents rod-like braided structure, and doping at the nickel site does not affect the main structure of the material. It can be seen from EDS data that the atomic ratio and weight ratio of nickel and cobalt elements are consistent with the molecular formula. The XPS spectra of the corresponding elements showed that Ni, Co and O elements were corresponding to NiCo2O4 materials. In conclusion, the result of physical morphology characterization analysis shows that the material is still in standard NiCo2O4 spinel structure.

The beryllium / strontium doped hydrogen storage alanate nano powders for concentrating solar thermal power applications

Nanopowders with MeH2 and Mem:1-7AlHn:4-7 (Me:Be/Sr) stoichiometry are synthesized with different aluminum: alkaline earth metal (beryllium and strontium) 0.1 atomic weight ratio step. Hydrogen storage nanoparticles (beryllium hydride-strontium hydride-strontium alanate) have orthorhombic crystal structure, with one step dissociation near 150 °C with ~8 wt% hydrogen in alane to one step in BeH2 at 250 °C with 18 wt%, to a one step in SrH2 at 240 °C with 2.1 wt%, and two steps in strontium alanate at 147 and 240 °C with 1.1 and 5.1 wt%. Particles are near 20–70 nm with small crystallite sizes about 6–21 nm in all hydride, alanate and residual ((metallic aluminum and beryllium) and alloyed aluminum, AlSr, Al4Sr, Al2Sr intermetallic) phases. Results indicate a controllable process for hydride and alanates nanopowders formation with exact dissociation temperatures/hydrogen release. Nanoparticles show consistent reversibility and cyclic behavior without reducing storage capacity, suitable for concentrating solar power applications.

Relations between metal ion characteristics and adsorption performance of graphene oxide: A comprehensive experimental and theoretical study

The adsorption performance of graphene oxide (GO) towards metallic hard (Na+, Mg2+), soft (Cd2+ and Pb2+) and borderline ions (Ni2+, Cu2+, Zn2+, Co2+) was studied experimentally giving the sequence of maximum Langmuir adsorption capacities Qm, mmol/g, as Na+ < Mg2+ < Co2+ < Cd2+ < Zn2+ < Ni2+ < Cu2+ < Pb2+. The results showed that the adsorption capacities Qm of hard ions were substantially lower than that of soft and borderline ones. The relationship between the Qm values of metal ions and their characteristics was studied using relative correlation analysis. The ion characteristics include atomic number AN, ionic radius r, change in ionization potential ΔIP, electronegativity Xm, atomic weight AW, covalent index Xm2r, absolute difference between electrochemical potential of the ion and that of its first stable reduced state ΔE0, absolute value of the first hydrolysis constant decimal logarithm |lgKOH|, atomic radius AR, atomic radius to atomic weight ratio AR/AW, polarization force or ionic index Z2/r and softness index σp. The Qm value exhibited positive correlation with r, △IP, Xm, Z2/r, AN/△IP, AW, Xm2/r and AN, while negative correlation was observed with △E0, |lgKOH|, σp, AR and AR/AW. The results allow the Qm values being predicted by the equation, the correlation coefficient R2 of which exceeds 0.885:Qm=0.338ΔIP-0.110|lgKOH|+0.114Z2/r+26.934σp-1.479AR-1.162Xm2r+0.115AN-3.059Density functional theory (DFT) was adopted to study the adsorption mechanism of metal ions at GO, taking Na+, Cu2+ and Pb2+ ions as examples. The results showed the adsorption energy Ead of GO-Na+ bond being negative indicating Na+ adsorption less likely resulting possibly in relatively low adsorption capacity of GO towards hard ions. The Ead values of GO bonds with Cu2+ and Pb2+ comprised the rows GO(O)-Cu2+ > GO(COOH)-Cu2+ > GO(OH)-Cu2+, and GO(COOH)-Pb2+ > GO(OH)-Pb2+ > GO(O)-Pb2+, respectively. The results provide guidelines in predicting the adsorption ability of GO adsorbent towards metal ions.

CeO2-Decorated ?-MnO2 Nanotubes: A Highly Efficient and Regenerable Sorbent for Elemental Mercury Removal from Natural Gas.

CeO2 nanoparticle-decorated ?-MnO2 nanotubes (NTs) were prepared and tested for elemental mercury (Hg0) vapor removal in simulated natural gas mixtures at ambient conditions. The composition which had the largest surface area and a relative Ce/Mn atomic weight ratio of around 35% exhibited a maximum Hg0 uptake capacity exceeding 20 mg?g?1 (2 wt %), as determined from measurements of mercury breakthrough which corresponded to 99.5% Hg0 removal efficiency over 96 h of exposure. This represents a significant improvement in the activity of pure metal oxides. Most importantly, the composite nanosorbent was repeatedly regenerated at 350 ?C and retained the 0.5% Hg0 breakthrough threshold. It was projected to be able to sustain 20 regeneration cycles, with the presence of acid gases, CO2, and H2S, not affecting its performance. This result is particularly important, considering that pure CeO2 manifests rather poor activity for Hg0 removal at ambient conditions, and hence, a synergistic effect in the composite nanomaterial was observed. This possibly results from the addition of facile oxygen vacancy formation at ?-MnO2 NTs and the increased amount of surface-adsorbed oxygen species.

Effect of the Addition of 3% Co in NiTi Alloy on Loading/Unloading Force

The study evaluated the loading-unloading force in the load-deflection curve of the fabricated NiTiCo and NiTi wires. Wire alloys with Nickel, Titanium, and Cobalt (purity-99.95%) with atomic weight ratio 47Ni:50Ti:3Co and 50.6Ni:49.4Ti were prepared, sliced, and cold-rolled at 30% reduction, followed by heat treatment in a furnace at 400oC for 1 hour. The specimens of wire size of 0.016 x 0.022 inch2 were cut and subjected to three-point bending test to investigate the load-deflection curve at deflection point 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mm. Descriptive statistic was used to evaluate each variables and independent t-test was used to compare between the groups. The results presented a load-deflection curve that resembled a typical superelastic wire. However, significant differences were seen in the loading-unloading forces between the two with an average loading force of 412.53g and 304.98g and unloading force of 292.40g and 208.08g for NiTiCo and NiTi wire, respectively. The force at each deflection point of NiTiCo in loading-unloading force was higher than NiTi wire. This study concluded that the addition of 3%Co in NiTi alloy can increase the loading-unloading force of NiTi wire but were within the range for orthodontic tooth movement.

Loading and Unloading Forces Following Addition of 5% Cu in Nickel-Titanium Alloy Used for Orthodontics

This study aims to address the amount of force delivered by a fabricated NiTiCu orthodontic wire with a ternary composition ratio of 46.0 Ni: 49.0 Ti: 5.0 Cu and to compare the results with a commercial NiTiCu35oC orthodontic archwire. Nickel (purity 99.9%), Titanium (purity 99.8%), and Copper (purity 99.9%) were used in this study with the atomic weight ratio 46.0 Ni: 49.0 Ti: 5.0 Cu. The elements were melted to form an alloy using an electrolytic arc furnace in argon gas atmosphere and homogenized at 800oC for 1 hr. The alloys were subsequently sliced into thin plates (1.5mm) by EDM wire cutting machine to obtain the specimens and were cold-rolled with 30% reduction followed by heat treatment in a furnace at 400oC for 1 hour. Then, the three newly fabricated NiTiCu specimens were cut in nearly identical wire sizes of 0.016 inch x0.022 inch. Commercial preformed Ormco NiTiCu35oC archwire with size 0.016 inch x 0.022 inches were used for comparative purposes. Three-point bending test was performed using a Universal Testing Machine to investigate the force of the load-deflection curve at oral temperature (36oC+ 1) with deflection points at 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mm. Descriptive statistics was used to evaluate each variable and independent t-test was used to analyze the differences between the groups. It was found that both NiTiCu wires presented typical superelastic properties as observed from the load-deflection curve. The average force was 341.70 g for loading, and 264.18 g for unloading for 46.0 Ni: 49.0 Ti: 5.0 Cu wire. Similarly, the values were 299.88 g for loading, and 201.96 g for unloading for Ormco NiTiCu35oC. There were significant differences (p&lt;0.05) in mean loading and unloading forces between the two NiTiCu wires. The deflection forces in loading and unloading force for Ormco NiTiCu at each point were less than 46.0 Ni: 49.0 Ti: 5.0 Cu wire, except at the deflection point of 0.25 mm. Regarding the force difference between each deflection point of loading and unloading force, Ormco NiTiCu35oC exerted less force than 46.0 Ni: 49.0 Ti: 5.0 Cu wire, except at difference deflection at 1.5-1.25 mm of unloading force. However, there were still within the acceptable limits for orthodontic use. It is concluded that the fabricated ternary alloy of 46.0 Ni: 49.0 Ti: 5.0 Cu (atomic weight) with 30% reduction and heat treatment at 400oC for 1 hr. and Ormco 35oC NiTiCu presented the characteristics of both superelastic and shape memory in their wire form. The unloading forces of both NiTiCu wires were in the range of orthodontic use. This should be a good foundation for further studies towards development of new orthodontic NiTiCu archwires.

Transparent ferromagnetic and semiconducting behavior in Fe-Dy-Tb based amorphous oxide films.

We report a class of amorphous thin film material comprising of transition (Fe) and Lanthanide metals (Dy and Tb) that show unique combination of functional properties. Films were deposited with different atomic weight ratio (R) of Fe to Lanthanide (Dy + Tb) using electron beam co-evaporation at room temperature. The films were found to be amorphous, with grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies indicating that the films were largely oxidized with a majority of the metal being in higher oxidation states. Films with R = 0.6 were semiconducting with visible light transmission due to a direct optical band-gap (2.49 eV), had low resistivity and sheet resistance (7.15 × 10−4 Ω-cm and ~200 Ω/sq respectively), and showed room temperature ferromagnetism. A metal to semiconductor transition with composition (for R < 11.9) also correlated well with the absence of any metallic Fe0 oxidation state in the R = 0.6 case as well as a significantly higher fraction of oxidized Dy. The combination of amorphous microstructure and room temperature electronic and magnetic properties could lead to the use of the material in multiple applications, including as a transparent conductor, active material in thin film transistors for display devices, and in spin-dependent electronics.

Recovery of deuterium from H–D gas mixture in thermal diffusion columns connected in series with countercurrent-flow transverse sampling streams

The equations for predicting the degrees of separation of H2, HD and D2 from H–D gas mixture by thermal diffusion in countercurrent-flow concentric-tube Frazier schemes of single and multiple columns, have been derived. The equations for predicting the recovery of deuterium (D) in HD and D2 were then obtained with the use of the atomic weight ratio. The degrees of separation, as well as separation factors, for deuterium recovery in the cryogenic-wall thermal diffusion devices were estimated, with the use of the experimental data obtained by Arita et al., 1998 and with the transport coefficients correlated in the previous work. Considerable improvement in deuterium recovery is achievable if a Frazier scheme with multiple columns is employed, instead of using the single-column device, either with the same column height, or with the same total sum of column heights, especially for the operation under larger volume flow rate and/or higher operating pressure. Further, countercurrent-flow operation is better than concurrent-flow operation in multi-column devices.

Methyl salicylate detection via electrochemical transients using nano spinel Co3O4 films

The mixed nano spinel Co3O4 films were fabricated through electrochemical deposition followed by peroxide oxidation and heat treatment. Electrochemical characteristics of the deposition and textural as well as morphological characteristics of the films were analyzed. Both 400 plane for Co3O4 and the 200 plane for CoO were noted. Based on IR studies, hydroxides decomposed into oxides on annealing. Oxide films are having the stoichiometric atomic weight ratio, O:Co as 1:2.7. Chronopotentiometric and chronoamperometric transients were recorded for the anodic oxidation of methyl salicylate using cobalt oxide films. Based on the electrochemical kinetic data, oxidation mechanism scheme is proposed and the net oxidation rate depends on sluggish charge-transfer limitations. Salicylate di-ion to 1, 2 benzoquinone is more favorable than 1, 4 benzoquinone derivative with four-electron transfer, whereas methoxide to formaldehyde involves two-electron transfer.

High pressure sintering of cubic boron nitride using Co–V–Al alloy as bonding media

Fine-grained polycrystalline cubic boron nitride compacts were prepared using the mixture of cubic BN and Co–V–Al powders at 5.6GPa and 1700°C for 0.5h. The weight percent of Co, V and Al to cubic BN powder was 10wt.% or 20wt.%. Results of electron dispersive spectrum were suggested that binder composition was changed from metallic binder of Co and V was dominant to VN and AlN mixture was dominant with increase of atomic percent of Al to BN in the sample. Microstructures of the sintered samples were observed by scanning electron microscope and back scattered electron image. The region of atomic weight ratio of Al to V that was about 1–5 showed homogeneously sintered microstructure of less than 3μm of cubic BN grain size. The Vickers hardness trend that showed higher values in the region of atomic weight ratio of Al to V was about 1–5. The highest Vickers hardness resulted in the present study was about 40.7GPa for the 20wt.% metallic binder that contained a 1.39 atomic weight ratio of Al to V and 0.5–2μm size of starting cubic BN powder was used.

Composition design rule for energy harvesting devices in piezoelectric perovskite ceramics

A composition design rule is proposed for energy harvesting devices in piezoelectric perovskite ceramics. For energy harvesting devices, a piezoelectric voltage coefficient (g33) as well as a piezoelectric distortion constant (d33) must be considered, because a high d33xg33 value indicates a high energy density. It is suggested that a large d33xg33 value can be obtained by tuning the magnitude of atomic weight ratio between A and B site (Rw=WA/WB) in ABO3 perovskite ceramics in this study. In addition, the various compositions were prepared in order to confirm the effect of crystal structure and RW on d33xg33 value in piezoelectric perovskite materials.

Secondary Ion Mass Spectrometry for the quantification of multiple minor and trace elements in forsterite–fayalite

Matrix effects in the olivine binary series are known to affect the determination of minor and trace elements by Secondary Ion Mass Spectrometry (SIMS). We use seven well-characterized, compositionally divergent reference materials (Fo100–Fo0.5) to calibrate these effects for accurate analyses of the forsterite (Fo) content and a suite of petrologically important minor and trace elements (Ca, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn) using SIMS.The forsterite (Fo) content and, concurrently, the concentrations of MgO, FeO, and SiO2 of an unknown sample are extracted from a calibration of R25Mg+/(R25Mg++R57Fe+) (RMX+ is the intensity ratio of an analyte ion to 30Si+ measured by SIMS) against accepted values for Fo for the seven reference materials, as originally determined by Electron Probe Microanalysis (EPMA). Traditional working lines (RMX+ versus accepted values for atomic weight ratio) for Ca, Ti, V, and Cr display near-linear relationships, whereas plots of Relative Sensitivity Factor (RSF) versus Fo content for Mn, Co, Ni, Cu, and Zn revealed significant non-linear variations with olivine composition (‘matrix effect’). RSF-based working lines for these elements yield polynomial regressions with strong correlations (R2∼0.99). This consequently enables a precise quantification of the matrix effect-biased elements over the complete range of natural olivine compositions.Comparison of SIMS vs. EPMA was performed using highly homogeneous mantle olivine (Fo90) from a garnet-peridotite (Western Gneiss Region, Norway) and more compositionally variable olivine (Fo74–89) from a volcanic ash deposit (2010 Eyjafjallajökull eruption, Iceland). SIMS determinations of Fo, Ni, and Mn compared accurately with those by EPMA – with the added advantage of ∼5ppm detection limit for Ni and Mn, and the analysis of Ca, Ti, V, Cr, Co, Cu, and Zn in the same sample volume. The capability of SIMS for precise quantification of Fo, Ni, Mn, and multiple trace elements is particularly valuable in petrogenetic and mineral deposit studies where olivine Fo compositions vary over a large range. For example, those pertaining to melt evolution in magmatic Ni–Cu–Co deposits.

Copper(I) Selenide Thin Films Deposited by a Solution-Based Method for Photovoltaic Applications

Polycrystalline Cu(2-x)Se thin films for solar cell application were deposited by a solution-based continuous flow reactor (CFR) process. In order to study the influence of reaction time on the physical, structural, and optical properties of the Cu(2-x)Se thin films, the deposition time for impinging varied from 2 min to 15 min. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectrophotometry, the optimum time to deposit the Cu(2-x)Se thin films using the CFR process was 10 min. The X-ray diffraction analysis revealed the cubic structure of the Cu(2-x)Se thin films annealed at 400 degrees C. The estimated band gap of the film was approximately 2.20 eV and its average grain size was around 150 nm with a film thickness of 1.8 microm. Energy dispersive analysis by X-ray (EDAX) showed that the atomic weight ratio of Cu to Se in the Cu(2-x)Se film deposited for 10 min was 1.8:1, i.e., x = 0.2. The chemical binding information of the Cu(2-x)Se thin film was also studied using X-ray photoelectron spectroscopy (XPS).

Radiocarbon Dating of Historical Parchments

A range of pretreatment methods was applied to 6 known-age historical parchments to investigate the most suitable methods for effectively removing contamination and ensuring accurate radiocarbon dates while minimizing unnecessary destruction of potentially valuable historical documents. The methods tested included an acid wash, different concentrations of acid-base-acid (ABA) pretreatments, the current routine ABA method applied at the Oxford Radiocarbon Accelerator Unit (ORAU) that includes an additional bleach treatment, and extraction of collagen. The C:N atomic weight ratio of the untreated and pretreated parchment fractions was observed to be a useful indicator of the presence or successful removal of contaminants. The pretreatment methods that produced the most accurate 14C dates and acceptable C:N ratios were found to be ABA protocols (without bleach) and collagen extraction; solvent washes and acid pretreatments alone were not sufficient to remove all contaminants and produce reliable 14C dates. The inclusion of a base wash did not affect the 14C dates of the samples, but did favorably influence the C:N ratio of the final product.

Synthesis and characterization of erbia and ceria doped calcia stabilized nanocrystalline zirconia based ceramics

Er2O3 doped calcia stabilized zirconia based inert matrix fuel containing CeO2 as a surrogate for PuO2 was fabricated for a wide range of concentration using the polymer-to-ceramic conversion technique via metal acetate preceramic hybrid polymer solutions. Samples were characterized by XRD, SEM and AFM techniques. Nanocrystallite size variation in the samples was evaluated using peak broadening values by means of the Scherrer formula. The smallest lattice constant was obtained for the sample containing Zr/Ca/Ce/Er atomic weight ratio of 74/11/10/5. The average grain diameters varied between 64 nm and 129 nm. SEM results show that, the smallest grain size was obtained for the sample containing Zr/Ce/Er atomic weight ratio of 22/2/1. Moreover, surface roughness characteristics of the samples were evaluated by different definitions using intermittent contact mode AFM.

Investigation of Relations between Atomic Number and Composition Weight Ratio in PZT and SMA and Prediction of Mechanical Behavior

In this paper there is presented the mechanical behavior of the one lead–zirconate–titanate by its atomicnumberanditscertainmechanicalbehaviorissimulatedbythemathematicalmodelingandABAQUSsoftwareforsmartmaterials,aswellaspredictionofmechanicalbehaviors. Alsointhissmartmaterial(Pb–Zr–Ti)thegrainsizeaccordingtomolarratioisstudied. Thismechanicalbehaviorismodeledbytheexponentialandpolynomialformulafromonetotendegree. Nexttherearedefinedthenewrelationsformechanicalbehaviorandcompositionweight ratio, between composed elements for triplex lead–zirconate–titanate and dual smart materials. Triplexlead–zirconate–titanatehasbeenselectedasmainandimportantmaterialforthedevelopmentofsmartstructures.In addition, the relation between atomic number and weight ratio in one smart material (Ni–Ti) is investigatedbriefly. Inthiswork,changeofresistanceandvoltage,pressure,grainsize,molarratio,residualstress,contentofzirconateandtheothermechanicalpropertiesarestudied.PACS:31.15.–p,31.10.+z,32.10.–f

A DMFC with Methanol-Tolerant-Carbon-Supported-Pt-Pd-Alloy Cathode

Methanol-tolerant Pt-Pd alloy catalysts supported on to carbon with varying Pt:Pd atomic ratios of 1:1, 2:1 and 3:1 are prepared by a novel wet-chemical method and characterized using powder XRD, XPS, FESEM, EDAX and TEM techniques. The optimum atomic weight ratio for Pt to Pd in the carbon-supported alloy catalyst as established by linear-sweep voltammetry (LSV) and cell polarization studies is found to be 2:1. A direct methanol fuel cell (DMFC) employing carbon-supported Pt-Pd (2:1) alloy (Pt-Pd/C) catalyst as the cathode catalyst delivers a peak-power density of 115 mW/cm2 at 70°C as compared to peak-power density of 60 mW/cm2 obtained with the DMFC employing carbon-supported Pt (Pt/C) catalyst operating under similar conditions. In the literature, DMFCs operating with Pt-TiO2 (2:1)/C and Pt-Au (2:1)/C methanol-tolerant cathodes are reported to exhibit maximum ORR activity among the group of these methanol-tolerant cathodes with varying catalysts compositions. Accordingly, the present study also provides an effective route to design methanol-tolerant-oxygen-reduction catalysts for DMFCs.

Carbon-Supported Pt-Pd Alloy as a Methanol-Tolerant-Oxygen-Reduction Electro-Catalyst for DMFCs

High-performance methanol-tolerant Pt-Pd alloy on carbon with varying Pt:Pd atomic ratio of 1:1, 2:1 and 3:1 was prepared by a facile wet-chemical method and characterized by XRD, FESEM and EDX techniques. The optimum atomic weight ratio of Pt to Pd in the carbon-supported alloy catalyst as established by linear-sweep voltammetry (LSV) and cell-polarization studies is determined to be 2:1. A direct methanol fuel cell (DMFC) comprising a carbon-supported Pt-Pd(2:1) alloy (1mgPt /cm2) as the cathode catalyst delivers a peak-power density of 115 mW/cm2 at 70°C in contrast with the peak-power density value of 60mW/cm2 delivered by the DMFC with carbon-supported Pt catalyst operating under similar conditions.

First-principles calculations of carbon clathrates: Comparison to silicon and germanium clathrates

We employ state-of-the-art first-principles calculations based on density-functional theory and density-functional perturbation theory to investigate relevant physical properties and phase diagram of the free guest type-I $(X\text{\ensuremath{-}}46)$ and type-II $(X\text{\ensuremath{-}}34)$ carbon clathrates. Their properties and those of silicon and germanium diamonds, and clathrates have been computed and compared within the same approach. We briefly present and discuss their structural, cohesive, and electronic properties. In particular, we present different results about electronic properties of carbon clathrates. From the symmetry analysis of electronic states around the band gap, we deduce their optical properties, and we forecast the effects of hypothetical-doped elements on their electronic band gap. We then report first-principles calculations of vibrational, thermodynamical, and elastic properties. Whereas vibrational properties of Si and Ge systems can be linked through their atomic weight ratio, we show that the vibrational properties of carbon structures differ strongly. Raman and infrared spectra of all clathrates are also calculated and compared. The effects of pressure and temperature on thermodynamical properties (heat capacity, entropy, thermal expansion, etc.) within static and quasiharmonic approximations are investigated. It is shown that thermodynamical properties of carbon clathrates and diamond present a similar evolution up to high pressures (100 GPa) and over a large range of temperatures ([0, 1500] K). Then we deduce the equilibrium phase diagram $(P,T)$ of C-2/C-34/C-46. We conclude the paper with a presentation of elastic properties computed from acoustic slopes.